adding a functional tree example
authorJames Craig <jcraig@apple.com>
Fri, 03 May 2013 10:55:23 -0700
changeset 226 bc18bbcb1bbf
parent 225 afe7e7d43e87
child 227 7422f4d31bac
adding a functional tree example
ARIA/1.0/tests/test-files/_functional/tree/ariatree.html
ARIA/1.0/tests/test-files/_functional/tree/ariatree2.html
ARIA/1.0/tests/test-files/_functional/tree/css/img/expander.gif
ARIA/1.0/tests/test-files/_functional/tree/css/treebox.css
ARIA/1.0/tests/test-files/_functional/tree/css/treesimple.css
ARIA/1.0/tests/test-files/_functional/tree/js/aria.js
ARIA/1.0/tests/test-files/_functional/tree/js/init.js
ARIA/1.0/tests/test-files/_functional/tree/js/prototype.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ARIA/1.0/tests/test-files/_functional/tree/ariatree.html	Fri May 03 10:55:23 2013 -0700
@@ -0,0 +1,106 @@
+<!DOCTYPE HTML><!-- HTML 5 -->
+<html lang="en">
+<head>
+	<title>ARIA Tree Example</title>
+	<meta http-equiv="Content-type" content="text/html; charset=utf-8">
+	<link rel="stylesheet" href="./css/treesimple.css" type="text/css">
+	<script type="text/javascript" src="./js/prototype.js"></script>
+	<script type="text/javascript" src="./js/aria.js"></script>
+	<script type="text/javascript" src="./js/init.js"></script>
+</head>
+<body>
+	
+	<h1>Directions</h1>
+	<ol>
+		<li>Tab into the tree control.</li>
+		<li>Use the up/down arrow keys to change the active descendant.</li>
+		<li>Use the right/left arrow keys to expand/collapse appropriate nodes.</li>
+	</ol>
+	
+	<p>Some <a href="javascript:$('tree0').focus();">focusable</a> content before the ARIA application.</p>
+
+	<div role="application">
+		<h1 id="treelabel">ARIA Tree Example</h1>
+		<ul id="tree0" role="tree" aria-labelledby="treelabel" aria-activedescendant="tree0_item0_2_0_1" tabindex="0">
+			<!-- all the ids and aria-* attributes are hardcoded here for sake of example (final version will use javascript to assign ids as needed) -->
+			<li id="tree0_item0" role="treeitem" aria-level="1" aria-expanded="true">
+				<!-- .expander becomes the javascript trigger for expand/collapse -->
+				<span class="expander"></span>
+				Animals
+				<ul role="group">
+					<li id="tree0_item0_0" role="treeitem" aria-level="2"><span>Birds</span></li>
+					<li id="tree0_item0_1" role="treeitem" aria-level="2" aria-expanded="false">
+						<span class="expander"></span>
+						Cats
+						<ul role="group">
+							<li id="tree0_item0_1_0" role="treeitem"aria-level="3">Siamese</li>
+							<li id="tree0_item0_1_1" role="treeitem" aria-level="3">Tabby</li>
+						</ul>
+					</li>
+					<li id="tree0_item0_2" role="treeitem" aria-level="2" aria-expanded="true">
+						<span class="expander"></span>
+						Dogs
+						<ul role="group">
+							<li id="tree0_item0_2_0" role="treeitem" aria-level="3" aria-expanded="true">
+								<span class="expander"></span>
+								Small Breeds
+								<ul role="group">
+									<li id="tree0_item0_2_0_0" role="treeitem" aria-level="4">Chihuahua</li>
+									<li id="tree0_item0_2_0_1" role="treeitem" aria-level="4">Italian Greyhound</li>
+									<li id="tree0_item0_2_0_2" role="treeitem" aria-level="4">Japanese Chin</li>
+								</ul>
+							</li>
+							<li id="tree0_item0_2_1" role="treeitem" aria-level="3" aria-expanded="false">
+								<span class="expander"></span>
+								Medium Breeds
+								<ul role="group">
+									<li id="tree0_item0_2_1_0" role="treeitem" aria-level="4">Beagle</li>
+									<li id="tree0_item0_2_1_1" role="treeitem" aria-level="4">Cocker Spaniel</li>
+									<li id="tree0_item0_2_1_2" role="treeitem" aria-level="4">Pit Bull</li>
+								</ul>
+							</li>
+							<li id="tree0_item0_2_2" role="treeitem" aria-level="3" aria-expanded="false">
+								<span class="expander"></span>
+								Large Breeds
+								<ul role="group">
+									<li id="tree0_item0_2_2_0" role="treeitem" aria-level="4">Afghan</li>
+									<li id="tree0_item0_2_2_1" role="treeitem" aria-level="4">Great Dane</li>
+									<li id="tree0_item0_2_2_2" role="treeitem" aria-level="4">Mastiff</li>
+								</ul>
+							</li>
+						</ul>
+					</li>
+				</ul>
+			</li>
+			<li id="tree0_item1" role="treeitem" aria-level="1" aria-expanded="true">
+				<span class="expander"></span>
+				Minerals
+				<ul role="group">
+					<li id="tree0_item1_0" role="treeitem" aria-level="2">Zinc</li>
+					<li id="tree0_item1_1" role="treeitem" aria-level="2" aria-expanded="false">
+						<span class="expander"></span>
+						Gold
+						<ul role="group">
+							<li id="tree0_item1_1_0" role="treeitem" aria-level="3">Yellow Gold</li>
+							<li id="tree0_item1_1_1" role="treeitem" aria-level="3">White Gold</li>
+						</ul>
+					</li>
+					<li id="tree0_item1_2" role="treeitem" aria-level="2">Silver</li>
+				</ul>
+			</li>
+			<li id="tree0_item2" role="treeitem" aria-level="1" aria-expanded="true">
+				<span class="expander"></span>
+				Vegetables
+				<ul role="group">
+					<li id="tree0_item2_0" role="treeitem" aria-level="2">Carrot</li>
+					<li id="tree0_item2_1" role="treeitem" aria-level="2">Tomato</li>
+					<li id="tree0_item2_2" role="treeitem" aria-level="2">Lettuce</li>
+				</ul>
+			</li>
+		</ul>
+	</div>
+	
+	<p>More <a href="javascript:$('tree0').focus();">focusable</a> content after the ARIA application.</p>
+	
+</body>
+</html>
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ARIA/1.0/tests/test-files/_functional/tree/ariatree2.html	Fri May 03 10:55:23 2013 -0700
@@ -0,0 +1,124 @@
+<!DOCTYPE HTML><!-- HTML 5 -->
+<html lang="en">
+<head>
+	<title>ARIA Tree Example</title>
+	<meta http-equiv="Content-type" content="text/html; charset=utf-8">
+	<link rel="stylesheet" href="./css/treebox.css" type="text/css">
+	<script type="text/javascript" src="./js/prototype.js"></script>
+	<script type="text/javascript" src="./js/aria.js"></script>
+	<script type="text/javascript" src="./js/init.js"></script>
+</head>
+<body>
+	
+	<h1>Directions</h1>
+	<ol>
+		<li>Tab into the tree control.</li>
+		<li>Use the up/down arrow keys to change the active descendant.</li>
+		<li>Use the right/left arrow keys to expand/collapse appropriate nodes.</li>
+	</ol>
+	
+	<p>Some <a href="javascript:$('tree0').focus();">focusable</a> content before the ARIA application.</p>
+
+	<div role="application">
+		<h1 id="treelabel">ARIA Tree Example</h1>
+		<ul id="tree0" role="tree" aria-labelledby="treelabel" aria-activedescendant="tree0_item0_2_0_1" tabindex="0">
+			<!-- all the ids and aria-* attributes are hardcoded here for sake of example (final version will use javascript to assign ids as needed) -->
+			<li id="tree0_item0" role="treeitem" aria-level="1" aria-expanded="true">
+				<!-- .expander becomes the javascript trigger for expand/collapse -->
+				<span>
+					<span class="expander"></span>
+					Animals
+				</span>
+				<ul role="group">
+					<li id="tree0_item0_0" role="treeitem" aria-level="2"><span>Birds</span></li>
+					<li id="tree0_item0_1" role="treeitem" aria-level="2" aria-expanded="false">
+						<span>
+							<span class="expander"></span>
+							Cats
+						</span>
+						<ul role="group">
+							<li id="tree0_item0_1_0" role="treeitem"aria-level="3"><span>Siamese</span></li>
+							<li id="tree0_item0_1_1" role="treeitem" aria-level="3"><span>Tabby</span></li>
+						</ul>
+					</li>
+					<li id="tree0_item0_2" role="treeitem" aria-level="2" aria-expanded="true">
+						<span>
+							<span class="expander"></span>
+							Dogs
+						</span>
+						<ul role="group">
+							<li id="tree0_item0_2_0" role="treeitem" aria-level="3" aria-expanded="true">
+								<span>
+									<span class="expander"></span>
+									Small Breeds
+								</span>
+								<ul role="group">
+									<li id="tree0_item0_2_0_0" role="treeitem" aria-level="4"><span>Chihuahua</span></li>
+									<li id="tree0_item0_2_0_1" role="treeitem" aria-level="4"><span>Italian Greyhound</span></li>
+									<li id="tree0_item0_2_0_2" role="treeitem" aria-level="4"><span>Japanese Chin</span></li>
+								</ul>
+							</li>
+							<li id="tree0_item0_2_1" role="treeitem" aria-level="3" aria-expanded="false">
+								<span>
+									<span class="expander"></span>
+									Medium Breeds
+								</span>
+								<ul role="group">
+									<li id="tree0_item0_2_1_0" role="treeitem" aria-level="4"><span>Beagle</span></li>
+									<li id="tree0_item0_2_1_1" role="treeitem" aria-level="4"><span>Cocker Spaniel</span></li>
+									<li id="tree0_item0_2_1_2" role="treeitem" aria-level="4"><span>Pit Bull</span></li>
+								</ul>
+							</li>
+							<li id="tree0_item0_2_2" role="treeitem" aria-level="3" aria-expanded="false">
+								<span>
+									<span class="expander"></span>
+									Large Breeds
+								</span>
+								<ul role="group">
+									<li id="tree0_item0_2_2_0" role="treeitem" aria-level="4"><span>Afghan</span></li>
+									<li id="tree0_item0_2_2_1" role="treeitem" aria-level="4"><span>Great Dane</span></li>
+									<li id="tree0_item0_2_2_2" role="treeitem" aria-level="4"><span>Mastiff</span></li>
+								</ul>
+							</li>
+						</ul>
+					</li>
+				</ul>
+			</li>
+			<li id="tree0_item1" role="treeitem" aria-level="1" aria-expanded="true">
+				<span>
+					<span class="expander"></span>
+					Minerals
+				</span>
+				<ul role="group">
+					<li id="tree0_item1_0" role="treeitem" aria-level="2"><span>Zinc</span></li>
+					<li id="tree0_item1_1" role="treeitem" aria-level="2" aria-expanded="false">
+						<span>
+							<span class="expander"></span>
+							Gold
+						</span>
+						<ul role="group">
+							<li id="tree0_item1_1_0" role="treeitem" aria-level="3"><span>Yellow Gold</span></li>
+							<li id="tree0_item1_1_1" role="treeitem" aria-level="3"><span>White Gold</span></li>
+						</ul>
+					</li>
+					<li id="tree0_item1_2" role="treeitem" aria-level="2"><span>Silver</span></li>
+				</ul>
+			</li>
+			<li id="tree0_item2" role="treeitem" aria-level="1" aria-expanded="true">
+				<span>
+					<span class="expander"></span>
+					Vegetables
+				</span>
+				<ul role="group">
+					<li id="tree0_item2_0" role="treeitem" aria-level="2"><span>Carrot</span></li>
+					<li id="tree0_item2_1" role="treeitem" aria-level="2"><span>Tomato</span></li>
+					<li id="tree0_item2_2" role="treeitem" aria-level="2"><span>Lettuce</span></li>
+				</ul>
+			</li>
+		</ul>
+	</div>
+	
+	<p>More <a href="javascript:$('tree0').focus();">focusable</a> content after the ARIA application.</p>
+	
+</body>
+</html>
Binary file ARIA/1.0/tests/test-files/_functional/tree/css/img/expander.gif has changed
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ARIA/1.0/tests/test-files/_functional/tree/css/treebox.css	Fri May 03 10:55:23 2013 -0700
@@ -0,0 +1,65 @@
+
+/* variant of treesimple.css, that adds slightly more complex styling. */
+
+html, body {
+	color:#333;
+	background-color:#fff;
+	font-family:"helvetica neue", arial, helvetica, sans-serif;
+	font-size:12px;
+	line-height:1.4em;
+}
+h1{
+	font-size:14px;
+}
+[role="tree"]{
+	border:solid 1px #000;
+	width:300px; /* hardcoded for example */
+	cursor:default;
+}
+ul[role="tree"], [role="tree"] li, [role="tree"] ul {
+	display:block;
+	list-style:none;
+	margin:0;
+	padding:0;
+}
+li[role="treeitem"] {
+	position:relative;
+}
+
+[role="treeitem"] > span{ display:block; }
+
+/* looks kinda redundant, but is necessary to get the full left bleed on sub-level items */
+[role="treeitem"] > span{ padding-left:15px; }
+[role="treeitem"] [role="treeitem"] > span{ padding-left:30px; }
+[role="treeitem"] [role="treeitem"] [role="treeitem"] > span{ padding-left:45px; }
+[role="treeitem"] [role="treeitem"] [role="treeitem"] [role="treeitem"] > span{ padding-left:60px; }
+[role="treeitem"] [role="treeitem"] [role="treeitem"] [role="treeitem"] [role="treeitem"] > span{ padding-left:75px; }
+
+.expander {
+	display:block;
+	position:absolute;
+	left:2px;
+	top:0.3em;
+	width:9px;
+	height:9px;
+	background:transparent url(./img/expander.gif) -9px 0 no-repeat;
+}
+[aria-expanded="false"] > * > .expander {
+	background-position:0 0;
+}
+[role="treeitem"] [role="treeitem"] .expander { left:17px; }
+[role="treeitem"] [role="treeitem"] [role="treeitem"] .expander { left:32px; }
+[role="treeitem"] [role="treeitem"] [role="treeitem"] [role="treeitem"] .expander { left:47px; }
+[role="treeitem"] [role="treeitem"] [role="treeitem"] [role="treeitem"] [role="treeitem"] .expander { left:62px; }
+
+
+[aria-expanded="false"] [role="group"] {
+	display:none;
+}
+[role="tree"] .activedescendant > span {
+	background-color:#ccc;
+}
+[role="tree"]:focus .activedescendant > span {
+	color:#fff;
+	background-color:#03c;
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ARIA/1.0/tests/test-files/_functional/tree/css/treesimple.css	Fri May 03 10:55:23 2013 -0700
@@ -0,0 +1,50 @@
+
+html, body {
+	color:#333;
+	background-color:#fff;
+	font-family:"helvetica neue", arial, helvetica, sans-serif;
+	font-size:12px;
+	line-height:1.4em;
+}
+h1{
+	font-size:14px;
+}
+[role="tree"]{
+	cursor:default;
+}
+ul[role="tree"], [role="tree"] li, [role="tree"] ul {
+	display:block;
+	list-style:none;
+	margin:0;
+	padding:0;
+}
+li[role="treeitem"] {
+	position:relative;
+	padding-left:15px;
+}
+.expander {
+	display:block;
+	position:absolute;
+	left:2px;
+	top:0.3em;
+	width:9px;
+	height:9px;
+	background:transparent url(./img/expander.gif) -9px 0 no-repeat;
+}
+[aria-expanded="false"] > * > .expander {
+	background-position:0 0;
+}
+[aria-expanded="false"] [role="group"] {
+	display:none;
+}
+[role="tree"] .activedescendant {
+	font-weight:bold;
+	color:#000;
+}
+[role="tree"]:focus .activedescendant{
+	color:#03c;
+}
+[role="tree"] .activedescendant [role="group"] {
+	font-weight:normal;
+	color:#000;
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ARIA/1.0/tests/test-files/_functional/tree/js/aria.js	Fri May 03 10:55:23 2013 -0700
@@ -0,0 +1,160 @@
+
+/* Aria Singleton */
+var Aria = {
+	Trees: new Array(), // instances of Aria.Tree Class
+	isEnabled: function(inNode){
+		// todo: this may need to check isEnabled on all parentNodes, inheritence of aria-enabled is ambiguous
+		if(inNode.getAttribute('aria-enabled') && inNode.getAttribute('aria-enabled').toLowerCase()=='false') return false;
+		else return true;
+	},
+	isExpanded: function(inNode){
+		if(inNode.getAttribute('aria-expanded') && inNode.getAttribute('aria-expanded').toLowerCase()=='false') return false;
+		else return true;
+	},
+	isTreeItem: function(inNode){
+		if(inNode.getAttribute('role') && inNode.getAttribute('role').toLowerCase()=='treeitem') return true;
+		else return false;
+	}
+};
+
+Aria.Tree = Class.create();
+Aria.Tree.prototype = {
+	initialize: function(inNode){
+		if(!$(inNode) && console.error) console.error('Error from aria.js: Aria.Tree instance initialized with invalid element, '+ inNode);
+		this.el = $(inNode);
+		this.index = Aria.Trees.length; // each tree should know its index in the Aria singleton's list, in order to concatenate id strings
+		this.strActiveDescendant = this.el.getAttribute('aria-activedescendant');
+		this.strDefaultActiveDescendant = 'tree'+this.index+'_item0'; // default first item
+		if(!$(this.strActiveDescendant)) this.strActiveDescendant = this.strDefaultActiveDescendant; // set to default if no existing activedescendant
+		this.setActiveDescendant($(this.strActiveDescendant));
+		
+		// set up event delegation on the tree node
+		Event.observe(this.el, 'click', this.handleClick.bindAsEventListener(this));
+		Event.observe(this.el, 'keydown', this.handleKeyPress.bindAsEventListener(this)); //webkit doesn't send keypress events for arrow keys, so use keydown instead
+		
+	},
+	getActiveDescendant: function(inNode){
+		if(inNode){ // if inNode (from event target), sets the activedescendant to nearest ancestor treeitem
+			var el = $(inNode);
+			while(el != this.el){
+				if(Aria.isTreeItem(el)) break; // exit the loop; we have the treeitem
+				el = el.parentNode;
+			}
+			if(el == this.el) {
+				this.setActiveDescendant(); // set to default activedescendant
+			} else {
+				this.setActiveDescendant(el);
+				return el;
+			}
+		} else {
+			return $(this.el.getAttribute('aria-activedescendant'));
+		}
+	},
+	getNextTreeItem: function(inNode){
+		var el = $(inNode);
+		var originalElm = $(inNode);
+		while(!Aria.isTreeItem(el) || el == originalElm){
+			if(Aria.isExpanded(el) && el.down()){ // should be el.down('[role="treeitem"]');
+				var elements = el.getElementsByTagName('*');
+				for(var i=0, c=elements.length; i<c; i++){
+					if(Aria.isTreeItem(elements[i])) return elements[i];
+				}
+			}
+			if(el.next()){
+				el = el.next();
+			} else {
+				while(!el.parentNode.next() && el.parentNode != this.el){
+					el = el.parentNode;
+				}
+				if(el.parentNode == this.el) return originalElm; // if no next items in tree, return current treeitem
+				else el = el.parentNode.next();
+			}
+		}
+		return el;
+	},
+	getPreviousTreeItem: function(inNode){
+		var el = $(inNode);
+		var originalElm = $(inNode);
+		while(!Aria.isTreeItem(el) || el == originalElm){
+			if(el.previous()){
+				el = el.previous();
+				// recursively choose last child node of previous el, as long as it's not in an collapsed node
+				if (el.down() && Aria.isExpanded(el)){
+					el = el.down();
+					while (el.next() || (el.down() && Aria.isExpanded(el))){
+						if (el.next()) el = el.next();
+						else el = el.down();
+					}
+				}
+			} else {
+				if(el.parentNode == this.el) return originalElm; // if no previous items in tree, return current treeitem
+				el = el.parentNode;
+			}
+		}
+		if(el == this.el) return originalElm; // if no previous items in tree, return current treeitem
+		return el;
+	},
+	handleClick: function(inEvent){
+		var target = inEvent.target; // get the click target
+		var el = this.getActiveDescendant(target);
+		if(target.className.indexOf('expander')>-1){ // if it's an expander widget
+			this.toggleExpanded(el); // toggle the aria-expanded attribute on activedescendant
+			Event.stop(inEvent); // and stop the event
+		}
+	},
+	handleKeyPress: function(inEvent){
+		switch(inEvent.keyCode){
+			// case Event.KEY_PAGEUP:   break;
+			// case Event.KEY_PAGEDOWN: break;
+			// case Event.KEY_END:      break;
+			// case Event.KEY_HOME:     break;
+			case Event.KEY_LEFT:     this.keyLeft();  break;
+			case Event.KEY_UP:       this.keyUp();    break;
+			case Event.KEY_RIGHT:    this.keyRight(); break;
+			case Event.KEY_DOWN:     this.keyDown();  break;
+			default: 
+				//console.log(inEvent.keyCode);
+				return;
+		}
+		Event.stop(inEvent);
+	},
+	keyLeft: function(){
+		var el = this.activeDescendant;
+		if(Aria.isExpanded(el)){
+			el.setAttribute('aria-expanded','false');
+			this.setActiveDescendant(this.activeDescendant);
+		}
+	},
+	keyUp: function(){
+		var el = this.activeDescendant;
+		this.setActiveDescendant(this.getPreviousTreeItem(el));
+	},
+	keyRight: function(){
+		var el = this.activeDescendant;
+		if(!Aria.isExpanded(el)){
+			el.setAttribute('aria-expanded','true');
+			this.setActiveDescendant(this.activeDescendant);
+		}
+	},
+	keyDown: function(){
+		var el = this.activeDescendant;
+		this.setActiveDescendant(this.getNextTreeItem(el));
+	},
+	setActiveDescendant: function(inNode){
+		Element.removeClassName(this.activeDescendant,'activedescendant')
+		if($(inNode)) this.activeDescendant = $(inNode);
+		else this.activeDescendant = $(this.strDefaultActiveDescendant);
+		Element.addClassName(this.activeDescendant,'activedescendant')
+		this.strActiveDescendant = this.activeDescendant.id;
+		this.el.setAttribute('aria-activedescendant', this.activeDescendant.id);
+	},
+	toggleExpanded: function(inNode){
+		var el = $(inNode);
+		if(Aria.isExpanded(el)){
+			el.setAttribute('aria-expanded','false');
+		} else {
+			el.setAttribute('aria-expanded','true');	
+		}
+		this.setActiveDescendant(el);
+	}
+};
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ARIA/1.0/tests/test-files/_functional/tree/js/init.js	Fri May 03 10:55:23 2013 -0700
@@ -0,0 +1,8 @@
+function myLoad(){
+	$$('[role="tree"]').each(function(elm){
+		// for each node where [role="tree"], create a new Aria.Tree instance and append it to array Aria.Trees
+		Aria.Trees.push(new Aria.Tree(elm));
+	});
+}
+Event.observe(window, 'load', myLoad); // will probably use onDOMContentLoaded instead of onLoad
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ARIA/1.0/tests/test-files/_functional/tree/js/prototype.js	Fri May 03 10:55:23 2013 -0700
@@ -0,0 +1,4184 @@
+/*  Prototype JavaScript framework, version 1.6.0
+ *  (c) 2005-2007 Sam Stephenson
+ *
+ *  Prototype is freely distributable under the terms of an MIT-style license.
+ *  For details, see the Prototype web site: http://www.prototypejs.org/
+ *
+ *--------------------------------------------------------------------------*/
+
+var Prototype = {
+  Version: '1.6.0',
+
+  Browser: {
+    IE:     !!(window.attachEvent && !window.opera),
+    Opera:  !!window.opera,
+    WebKit: navigator.userAgent.indexOf('AppleWebKit/') > -1,
+    Gecko:  navigator.userAgent.indexOf('Gecko') > -1 && navigator.userAgent.indexOf('KHTML') == -1,
+    MobileSafari: !!navigator.userAgent.match(/Apple.*Mobile.*Safari/)
+  },
+
+  BrowserFeatures: {
+    XPath: !!document.evaluate,
+    ElementExtensions: !!window.HTMLElement,
+    SpecificElementExtensions:
+      document.createElement('div').__proto__ &&
+      document.createElement('div').__proto__ !==
+        document.createElement('form').__proto__
+  },
+
+  ScriptFragment: '<script[^>]*>([\\S\\s]*?)<\/script>',
+  JSONFilter: /^\/\*-secure-([\s\S]*)\*\/\s*$/,
+
+  emptyFunction: function() { },
+  K: function(x) { return x }
+};
+
+if (Prototype.Browser.MobileSafari)
+  Prototype.BrowserFeatures.SpecificElementExtensions = false;
+
+if (Prototype.Browser.WebKit)
+  Prototype.BrowserFeatures.XPath = false;
+
+/* Based on Alex Arnell's inheritance implementation. */
+var Class = {
+  create: function() {
+    var parent = null, properties = $A(arguments);
+    if (Object.isFunction(properties[0]))
+      parent = properties.shift();
+
+    function klass() {
+      this.initialize.apply(this, arguments);
+    }
+
+    Object.extend(klass, Class.Methods);
+    klass.superclass = parent;
+    klass.subclasses = [];
+
+    if (parent) {
+      var subclass = function() { };
+      subclass.prototype = parent.prototype;
+      klass.prototype = new subclass;
+      parent.subclasses.push(klass);
+    }
+
+    for (var i = 0; i < properties.length; i++)
+      klass.addMethods(properties[i]);
+
+    if (!klass.prototype.initialize)
+      klass.prototype.initialize = Prototype.emptyFunction;
+
+    klass.prototype.constructor = klass;
+
+    return klass;
+  }
+};
+
+Class.Methods = {
+  addMethods: function(source) {
+    var ancestor   = this.superclass && this.superclass.prototype;
+    var properties = Object.keys(source);
+
+    if (!Object.keys({ toString: true }).length)
+      properties.push("toString", "valueOf");
+
+    for (var i = 0, length = properties.length; i < length; i++) {
+      var property = properties[i], value = source[property];
+      if (ancestor && Object.isFunction(value) &&
+          value.argumentNames().first() == "$super") {
+        var method = value, value = Object.extend((function(m) {
+          return function() { return ancestor[m].apply(this, arguments) };
+        })(property).wrap(method), {
+          valueOf:  function() { return method },
+          toString: function() { return method.toString() }
+        });
+      }
+      this.prototype[property] = value;
+    }
+
+    return this;
+  }
+};
+
+var Abstract = { };
+
+Object.extend = function(destination, source) {
+  for (var property in source)
+    destination[property] = source[property];
+  return destination;
+};
+
+Object.extend(Object, {
+  inspect: function(object) {
+    try {
+      if (object === undefined) return 'undefined';
+      if (object === null) return 'null';
+      return object.inspect ? object.inspect() : object.toString();
+    } catch (e) {
+      if (e instanceof RangeError) return '...';
+      throw e;
+    }
+  },
+
+  toJSON: function(object) {
+    var type = typeof object;
+    switch (type) {
+      case 'undefined':
+      case 'function':
+      case 'unknown': return;
+      case 'boolean': return object.toString();
+    }
+
+    if (object === null) return 'null';
+    if (object.toJSON) return object.toJSON();
+    if (Object.isElement(object)) return;
+
+    var results = [];
+    for (var property in object) {
+      var value = Object.toJSON(object[property]);
+      if (value !== undefined)
+        results.push(property.toJSON() + ': ' + value);
+    }
+
+    return '{' + results.join(', ') + '}';
+  },
+
+  toQueryString: function(object) {
+    return $H(object).toQueryString();
+  },
+
+  toHTML: function(object) {
+    return object && object.toHTML ? object.toHTML() : String.interpret(object);
+  },
+
+  keys: function(object) {
+    var keys = [];
+    for (var property in object)
+      keys.push(property);
+    return keys;
+  },
+
+  values: function(object) {
+    var values = [];
+    for (var property in object)
+      values.push(object[property]);
+    return values;
+  },
+
+  clone: function(object) {
+    return Object.extend({ }, object);
+  },
+
+  isElement: function(object) {
+    return object && object.nodeType == 1;
+  },
+
+  isArray: function(object) {
+    return object && object.constructor === Array;
+  },
+
+  isHash: function(object) {
+    return object instanceof Hash;
+  },
+
+  isFunction: function(object) {
+    return typeof object == "function";
+  },
+
+  isString: function(object) {
+    return typeof object == "string";
+  },
+
+  isNumber: function(object) {
+    return typeof object == "number";
+  },
+
+  isUndefined: function(object) {
+    return typeof object == "undefined";
+  }
+});
+
+Object.extend(Function.prototype, {
+  argumentNames: function() {
+    var names = this.toString().match(/^[\s\(]*function[^(]*\((.*?)\)/)[1].split(",").invoke("strip");
+    return names.length == 1 && !names[0] ? [] : names;
+  },
+
+  bind: function() {
+    if (arguments.length < 2 && arguments[0] === undefined) return this;
+    var __method = this, args = $A(arguments), object = args.shift();
+    return function() {
+      return __method.apply(object, args.concat($A(arguments)));
+    }
+  },
+
+  bindAsEventListener: function() {
+    var __method = this, args = $A(arguments), object = args.shift();
+    return function(event) {
+      return __method.apply(object, [event || window.event].concat(args));
+    }
+  },
+
+  curry: function() {
+    if (!arguments.length) return this;
+    var __method = this, args = $A(arguments);
+    return function() {
+      return __method.apply(this, args.concat($A(arguments)));
+    }
+  },
+
+  delay: function() {
+    var __method = this, args = $A(arguments), timeout = args.shift() * 1000;
+    return window.setTimeout(function() {
+      return __method.apply(__method, args);
+    }, timeout);
+  },
+
+  wrap: function(wrapper) {
+    var __method = this;
+    return function() {
+      return wrapper.apply(this, [__method.bind(this)].concat($A(arguments)));
+    }
+  },
+
+  methodize: function() {
+    if (this._methodized) return this._methodized;
+    var __method = this;
+    return this._methodized = function() {
+      return __method.apply(null, [this].concat($A(arguments)));
+    };
+  }
+});
+
+Function.prototype.defer = Function.prototype.delay.curry(0.01);
+
+Date.prototype.toJSON = function() {
+  return '"' + this.getUTCFullYear() + '-' +
+    (this.getUTCMonth() + 1).toPaddedString(2) + '-' +
+    this.getUTCDate().toPaddedString(2) + 'T' +
+    this.getUTCHours().toPaddedString(2) + ':' +
+    this.getUTCMinutes().toPaddedString(2) + ':' +
+    this.getUTCSeconds().toPaddedString(2) + 'Z"';
+};
+
+var Try = {
+  these: function() {
+    var returnValue;
+
+    for (var i = 0, length = arguments.length; i < length; i++) {
+      var lambda = arguments[i];
+      try {
+        returnValue = lambda();
+        break;
+      } catch (e) { }
+    }
+
+    return returnValue;
+  }
+};
+
+RegExp.prototype.match = RegExp.prototype.test;
+
+RegExp.escape = function(str) {
+  return String(str).replace(/([.*+?^=!:${}()|[\]\/\\])/g, '\\$1');
+};
+
+/*--------------------------------------------------------------------------*/
+
+var PeriodicalExecuter = Class.create({
+  initialize: function(callback, frequency) {
+    this.callback = callback;
+    this.frequency = frequency;
+    this.currentlyExecuting = false;
+
+    this.registerCallback();
+  },
+
+  registerCallback: function() {
+    this.timer = setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
+  },
+
+  execute: function() {
+    this.callback(this);
+  },
+
+  stop: function() {
+    if (!this.timer) return;
+    clearInterval(this.timer);
+    this.timer = null;
+  },
+
+  onTimerEvent: function() {
+    if (!this.currentlyExecuting) {
+      try {
+        this.currentlyExecuting = true;
+        this.execute();
+      } finally {
+        this.currentlyExecuting = false;
+      }
+    }
+  }
+});
+Object.extend(String, {
+  interpret: function(value) {
+    return value == null ? '' : String(value);
+  },
+  specialChar: {
+    '\b': '\\b',
+    '\t': '\\t',
+    '\n': '\\n',
+    '\f': '\\f',
+    '\r': '\\r',
+    '\\': '\\\\'
+  }
+});
+
+Object.extend(String.prototype, {
+  gsub: function(pattern, replacement) {
+    var result = '', source = this, match;
+    replacement = arguments.callee.prepareReplacement(replacement);
+
+    while (source.length > 0) {
+      if (match = source.match(pattern)) {
+        result += source.slice(0, match.index);
+        result += String.interpret(replacement(match));
+        source  = source.slice(match.index + match[0].length);
+      } else {
+        result += source, source = '';
+      }
+    }
+    return result;
+  },
+
+  sub: function(pattern, replacement, count) {
+    replacement = this.gsub.prepareReplacement(replacement);
+    count = count === undefined ? 1 : count;
+
+    return this.gsub(pattern, function(match) {
+      if (--count < 0) return match[0];
+      return replacement(match);
+    });
+  },
+
+  scan: function(pattern, iterator) {
+    this.gsub(pattern, iterator);
+    return String(this);
+  },
+
+  truncate: function(length, truncation) {
+    length = length || 30;
+    truncation = truncation === undefined ? '...' : truncation;
+    return this.length > length ?
+      this.slice(0, length - truncation.length) + truncation : String(this);
+  },
+
+  strip: function() {
+    return this.replace(/^\s+/, '').replace(/\s+$/, '');
+  },
+
+  stripTags: function() {
+    return this.replace(/<\/?[^>]+>/gi, '');
+  },
+
+  stripScripts: function() {
+    return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');
+  },
+
+  extractScripts: function() {
+    var matchAll = new RegExp(Prototype.ScriptFragment, 'img');
+    var matchOne = new RegExp(Prototype.ScriptFragment, 'im');
+    return (this.match(matchAll) || []).map(function(scriptTag) {
+      return (scriptTag.match(matchOne) || ['', ''])[1];
+    });
+  },
+
+  evalScripts: function() {
+    return this.extractScripts().map(function(script) { return eval(script) });
+  },
+
+  escapeHTML: function() {
+    var self = arguments.callee;
+    self.text.data = this;
+    return self.div.innerHTML;
+  },
+
+  unescapeHTML: function() {
+    var div = new Element('div');
+    div.innerHTML = this.stripTags();
+    return div.childNodes[0] ? (div.childNodes.length > 1 ?
+      $A(div.childNodes).inject('', function(memo, node) { return memo+node.nodeValue }) :
+      div.childNodes[0].nodeValue) : '';
+  },
+
+  toQueryParams: function(separator) {
+    var match = this.strip().match(/([^?#]*)(#.*)?$/);
+    if (!match) return { };
+
+    return match[1].split(separator || '&').inject({ }, function(hash, pair) {
+      if ((pair = pair.split('='))[0]) {
+        var key = decodeURIComponent(pair.shift());
+        var value = pair.length > 1 ? pair.join('=') : pair[0];
+        if (value != undefined) value = decodeURIComponent(value);
+
+        if (key in hash) {
+          if (!Object.isArray(hash[key])) hash[key] = [hash[key]];
+          hash[key].push(value);
+        }
+        else hash[key] = value;
+      }
+      return hash;
+    });
+  },
+
+  toArray: function() {
+    return this.split('');
+  },
+
+  succ: function() {
+    return this.slice(0, this.length - 1) +
+      String.fromCharCode(this.charCodeAt(this.length - 1) + 1);
+  },
+
+  times: function(count) {
+    return count < 1 ? '' : new Array(count + 1).join(this);
+  },
+
+  camelize: function() {
+    var parts = this.split('-'), len = parts.length;
+    if (len == 1) return parts[0];
+
+    var camelized = this.charAt(0) == '-'
+      ? parts[0].charAt(0).toUpperCase() + parts[0].substring(1)
+      : parts[0];
+
+    for (var i = 1; i < len; i++)
+      camelized += parts[i].charAt(0).toUpperCase() + parts[i].substring(1);
+
+    return camelized;
+  },
+
+  capitalize: function() {
+    return this.charAt(0).toUpperCase() + this.substring(1).toLowerCase();
+  },
+
+  underscore: function() {
+    return this.gsub(/::/, '/').gsub(/([A-Z]+)([A-Z][a-z])/,'#{1}_#{2}').gsub(/([a-z\d])([A-Z])/,'#{1}_#{2}').gsub(/-/,'_').toLowerCase();
+  },
+
+  dasherize: function() {
+    return this.gsub(/_/,'-');
+  },
+
+  inspect: function(useDoubleQuotes) {
+    var escapedString = this.gsub(/[\x00-\x1f\\]/, function(match) {
+      var character = String.specialChar[match[0]];
+      return character ? character : '\\u00' + match[0].charCodeAt().toPaddedString(2, 16);
+    });
+    if (useDoubleQuotes) return '"' + escapedString.replace(/"/g, '\\"') + '"';
+    return "'" + escapedString.replace(/'/g, '\\\'') + "'";
+  },
+
+  toJSON: function() {
+    return this.inspect(true);
+  },
+
+  unfilterJSON: function(filter) {
+    return this.sub(filter || Prototype.JSONFilter, '#{1}');
+  },
+
+  isJSON: function() {
+    var str = this.replace(/\\./g, '@').replace(/"[^"\\\n\r]*"/g, '');
+    return (/^[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t]*$/).test(str);
+  },
+
+  evalJSON: function(sanitize) {
+    var json = this.unfilterJSON();
+    try {
+      if (!sanitize || json.isJSON()) return eval('(' + json + ')');
+    } catch (e) { }
+    throw new SyntaxError('Badly formed JSON string: ' + this.inspect());
+  },
+
+  include: function(pattern) {
+    return this.indexOf(pattern) > -1;
+  },
+
+  startsWith: function(pattern) {
+    return this.indexOf(pattern) === 0;
+  },
+
+  endsWith: function(pattern) {
+    var d = this.length - pattern.length;
+    return d >= 0 && this.lastIndexOf(pattern) === d;
+  },
+
+  empty: function() {
+    return this == '';
+  },
+
+  blank: function() {
+    return /^\s*$/.test(this);
+  },
+
+  interpolate: function(object, pattern) {
+    return new Template(this, pattern).evaluate(object);
+  }
+});
+
+if (Prototype.Browser.WebKit || Prototype.Browser.IE) Object.extend(String.prototype, {
+  escapeHTML: function() {
+    return this.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;');
+  },
+  unescapeHTML: function() {
+    return this.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>');
+  }
+});
+
+String.prototype.gsub.prepareReplacement = function(replacement) {
+  if (Object.isFunction(replacement)) return replacement;
+  var template = new Template(replacement);
+  return function(match) { return template.evaluate(match) };
+};
+
+String.prototype.parseQuery = String.prototype.toQueryParams;
+
+Object.extend(String.prototype.escapeHTML, {
+  div:  document.createElement('div'),
+  text: document.createTextNode('')
+});
+
+with (String.prototype.escapeHTML) div.appendChild(text);
+
+var Template = Class.create({
+  initialize: function(template, pattern) {
+    this.template = template.toString();
+    this.pattern = pattern || Template.Pattern;
+  },
+
+  evaluate: function(object) {
+    if (Object.isFunction(object.toTemplateReplacements))
+      object = object.toTemplateReplacements();
+
+    return this.template.gsub(this.pattern, function(match) {
+      if (object == null) return '';
+
+      var before = match[1] || '';
+      if (before == '\\') return match[2];
+
+      var ctx = object, expr = match[3];
+      var pattern = /^([^.[]+|\[((?:.*?[^\\])?)\])(\.|\[|$)/, match = pattern.exec(expr);
+      if (match == null) return before;
+
+      while (match != null) {
+        var comp = match[1].startsWith('[') ? match[2].gsub('\\\\]', ']') : match[1];
+        ctx = ctx[comp];
+        if (null == ctx || '' == match[3]) break;
+        expr = expr.substring('[' == match[3] ? match[1].length : match[0].length);
+        match = pattern.exec(expr);
+      }
+
+      return before + String.interpret(ctx);
+    }.bind(this));
+  }
+});
+Template.Pattern = /(^|.|\r|\n)(#\{(.*?)\})/;
+
+var $break = { };
+
+var Enumerable = {
+  each: function(iterator, context) {
+    var index = 0;
+    iterator = iterator.bind(context);
+    try {
+      this._each(function(value) {
+        iterator(value, index++);
+      });
+    } catch (e) {
+      if (e != $break) throw e;
+    }
+    return this;
+  },
+
+  eachSlice: function(number, iterator, context) {
+    iterator = iterator ? iterator.bind(context) : Prototype.K;
+    var index = -number, slices = [], array = this.toArray();
+    while ((index += number) < array.length)
+      slices.push(array.slice(index, index+number));
+    return slices.collect(iterator, context);
+  },
+
+  all: function(iterator, context) {
+    iterator = iterator ? iterator.bind(context) : Prototype.K;
+    var result = true;
+    this.each(function(value, index) {
+      result = result && !!iterator(value, index);
+      if (!result) throw $break;
+    });
+    return result;
+  },
+
+  any: function(iterator, context) {
+    iterator = iterator ? iterator.bind(context) : Prototype.K;
+    var result = false;
+    this.each(function(value, index) {
+      if (result = !!iterator(value, index))
+        throw $break;
+    });
+    return result;
+  },
+
+  collect: function(iterator, context) {
+    iterator = iterator ? iterator.bind(context) : Prototype.K;
+    var results = [];
+    this.each(function(value, index) {
+      results.push(iterator(value, index));
+    });
+    return results;
+  },
+
+  detect: function(iterator, context) {
+    iterator = iterator.bind(context);
+    var result;
+    this.each(function(value, index) {
+      if (iterator(value, index)) {
+        result = value;
+        throw $break;
+      }
+    });
+    return result;
+  },
+
+  findAll: function(iterator, context) {
+    iterator = iterator.bind(context);
+    var results = [];
+    this.each(function(value, index) {
+      if (iterator(value, index))
+        results.push(value);
+    });
+    return results;
+  },
+
+  grep: function(filter, iterator, context) {
+    iterator = iterator ? iterator.bind(context) : Prototype.K;
+    var results = [];
+
+    if (Object.isString(filter))
+      filter = new RegExp(filter);
+
+    this.each(function(value, index) {
+      if (filter.match(value))
+        results.push(iterator(value, index));
+    });
+    return results;
+  },
+
+  include: function(object) {
+    if (Object.isFunction(this.indexOf))
+      if (this.indexOf(object) != -1) return true;
+
+    var found = false;
+    this.each(function(value) {
+      if (value == object) {
+        found = true;
+        throw $break;
+      }
+    });
+    return found;
+  },
+
+  inGroupsOf: function(number, fillWith) {
+    fillWith = fillWith === undefined ? null : fillWith;
+    return this.eachSlice(number, function(slice) {
+      while(slice.length < number) slice.push(fillWith);
+      return slice;
+    });
+  },
+
+  inject: function(memo, iterator, context) {
+    iterator = iterator.bind(context);
+    this.each(function(value, index) {
+      memo = iterator(memo, value, index);
+    });
+    return memo;
+  },
+
+  invoke: function(method) {
+    var args = $A(arguments).slice(1);
+    return this.map(function(value) {
+      return value[method].apply(value, args);
+    });
+  },
+
+  max: function(iterator, context) {
+    iterator = iterator ? iterator.bind(context) : Prototype.K;
+    var result;
+    this.each(function(value, index) {
+      value = iterator(value, index);
+      if (result == undefined || value >= result)
+        result = value;
+    });
+    return result;
+  },
+
+  min: function(iterator, context) {
+    iterator = iterator ? iterator.bind(context) : Prototype.K;
+    var result;
+    this.each(function(value, index) {
+      value = iterator(value, index);
+      if (result == undefined || value < result)
+        result = value;
+    });
+    return result;
+  },
+
+  partition: function(iterator, context) {
+    iterator = iterator ? iterator.bind(context) : Prototype.K;
+    var trues = [], falses = [];
+    this.each(function(value, index) {
+      (iterator(value, index) ?
+        trues : falses).push(value);
+    });
+    return [trues, falses];
+  },
+
+  pluck: function(property) {
+    var results = [];
+    this.each(function(value) {
+      results.push(value[property]);
+    });
+    return results;
+  },
+
+  reject: function(iterator, context) {
+    iterator = iterator.bind(context);
+    var results = [];
+    this.each(function(value, index) {
+      if (!iterator(value, index))
+        results.push(value);
+    });
+    return results;
+  },
+
+  sortBy: function(iterator, context) {
+    iterator = iterator.bind(context);
+    return this.map(function(value, index) {
+      return {value: value, criteria: iterator(value, index)};
+    }).sort(function(left, right) {
+      var a = left.criteria, b = right.criteria;
+      return a < b ? -1 : a > b ? 1 : 0;
+    }).pluck('value');
+  },
+
+  toArray: function() {
+    return this.map();
+  },
+
+  zip: function() {
+    var iterator = Prototype.K, args = $A(arguments);
+    if (Object.isFunction(args.last()))
+      iterator = args.pop();
+
+    var collections = [this].concat(args).map($A);
+    return this.map(function(value, index) {
+      return iterator(collections.pluck(index));
+    });
+  },
+
+  size: function() {
+    return this.toArray().length;
+  },
+
+  inspect: function() {
+    return '#<Enumerable:' + this.toArray().inspect() + '>';
+  }
+};
+
+Object.extend(Enumerable, {
+  map:     Enumerable.collect,
+  find:    Enumerable.detect,
+  select:  Enumerable.findAll,
+  filter:  Enumerable.findAll,
+  member:  Enumerable.include,
+  entries: Enumerable.toArray,
+  every:   Enumerable.all,
+  some:    Enumerable.any
+});
+function $A(iterable) {
+  if (!iterable) return [];
+  if (iterable.toArray) return iterable.toArray();
+  var length = iterable.length, results = new Array(length);
+  while (length--) results[length] = iterable[length];
+  return results;
+}
+
+if (Prototype.Browser.WebKit) {
+  function $A(iterable) {
+    if (!iterable) return [];
+    if (!(Object.isFunction(iterable) && iterable == '[object NodeList]') &&
+        iterable.toArray) return iterable.toArray();
+    var length = iterable.length, results = new Array(length);
+    while (length--) results[length] = iterable[length];
+    return results;
+  }
+}
+
+Array.from = $A;
+
+Object.extend(Array.prototype, Enumerable);
+
+if (!Array.prototype._reverse) Array.prototype._reverse = Array.prototype.reverse;
+
+Object.extend(Array.prototype, {
+  _each: function(iterator) {
+    for (var i = 0, length = this.length; i < length; i++)
+      iterator(this[i]);
+  },
+
+  clear: function() {
+    this.length = 0;
+    return this;
+  },
+
+  first: function() {
+    return this[0];
+  },
+
+  last: function() {
+    return this[this.length - 1];
+  },
+
+  compact: function() {
+    return this.select(function(value) {
+      return value != null;
+    });
+  },
+
+  flatten: function() {
+    return this.inject([], function(array, value) {
+      return array.concat(Object.isArray(value) ?
+        value.flatten() : [value]);
+    });
+  },
+
+  without: function() {
+    var values = $A(arguments);
+    return this.select(function(value) {
+      return !values.include(value);
+    });
+  },
+
+  reverse: function(inline) {
+    return (inline !== false ? this : this.toArray())._reverse();
+  },
+
+  reduce: function() {
+    return this.length > 1 ? this : this[0];
+  },
+
+  uniq: function(sorted) {
+    return this.inject([], function(array, value, index) {
+      if (0 == index || (sorted ? array.last() != value : !array.include(value)))
+        array.push(value);
+      return array;
+    });
+  },
+
+  intersect: function(array) {
+    return this.uniq().findAll(function(item) {
+      return array.detect(function(value) { return item === value });
+    });
+  },
+
+  clone: function() {
+    return [].concat(this);
+  },
+
+  size: function() {
+    return this.length;
+  },
+
+  inspect: function() {
+    return '[' + this.map(Object.inspect).join(', ') + ']';
+  },
+
+  toJSON: function() {
+    var results = [];
+    this.each(function(object) {
+      var value = Object.toJSON(object);
+      if (value !== undefined) results.push(value);
+    });
+    return '[' + results.join(', ') + ']';
+  }
+});
+
+// use native browser JS 1.6 implementation if available
+if (Object.isFunction(Array.prototype.forEach))
+  Array.prototype._each = Array.prototype.forEach;
+
+if (!Array.prototype.indexOf) Array.prototype.indexOf = function(item, i) {
+  i || (i = 0);
+  var length = this.length;
+  if (i < 0) i = length + i;
+  for (; i < length; i++)
+    if (this[i] === item) return i;
+  return -1;
+};
+
+if (!Array.prototype.lastIndexOf) Array.prototype.lastIndexOf = function(item, i) {
+  i = isNaN(i) ? this.length : (i < 0 ? this.length + i : i) + 1;
+  var n = this.slice(0, i).reverse().indexOf(item);
+  return (n < 0) ? n : i - n - 1;
+};
+
+Array.prototype.toArray = Array.prototype.clone;
+
+function $w(string) {
+  if (!Object.isString(string)) return [];
+  string = string.strip();
+  return string ? string.split(/\s+/) : [];
+}
+
+if (Prototype.Browser.Opera){
+  Array.prototype.concat = function() {
+    var array = [];
+    for (var i = 0, length = this.length; i < length; i++) array.push(this[i]);
+    for (var i = 0, length = arguments.length; i < length; i++) {
+      if (Object.isArray(arguments[i])) {
+        for (var j = 0, arrayLength = arguments[i].length; j < arrayLength; j++)
+          array.push(arguments[i][j]);
+      } else {
+        array.push(arguments[i]);
+      }
+    }
+    return array;
+  };
+}
+Object.extend(Number.prototype, {
+  toColorPart: function() {
+    return this.toPaddedString(2, 16);
+  },
+
+  succ: function() {
+    return this + 1;
+  },
+
+  times: function(iterator) {
+    $R(0, this, true).each(iterator);
+    return this;
+  },
+
+  toPaddedString: function(length, radix) {
+    var string = this.toString(radix || 10);
+    return '0'.times(length - string.length) + string;
+  },
+
+  toJSON: function() {
+    return isFinite(this) ? this.toString() : 'null';
+  }
+});
+
+$w('abs round ceil floor').each(function(method){
+  Number.prototype[method] = Math[method].methodize();
+});
+function $H(object) {
+  return new Hash(object);
+};
+
+var Hash = Class.create(Enumerable, (function() {
+  if (function() {
+    var i = 0, Test = function(value) { this.key = value };
+    Test.prototype.key = 'foo';
+    for (var property in new Test('bar')) i++;
+    return i > 1;
+  }()) {
+    function each(iterator) {
+      var cache = [];
+      for (var key in this._object) {
+        var value = this._object[key];
+        if (cache.include(key)) continue;
+        cache.push(key);
+        var pair = [key, value];
+        pair.key = key;
+        pair.value = value;
+        iterator(pair);
+      }
+    }
+  } else {
+    function each(iterator) {
+      for (var key in this._object) {
+        var value = this._object[key], pair = [key, value];
+        pair.key = key;
+        pair.value = value;
+        iterator(pair);
+      }
+    }
+  }
+
+  function toQueryPair(key, value) {
+    if (Object.isUndefined(value)) return key;
+    return key + '=' + encodeURIComponent(String.interpret(value));
+  }
+
+  return {
+    initialize: function(object) {
+      this._object = Object.isHash(object) ? object.toObject() : Object.clone(object);
+    },
+
+    _each: each,
+
+    set: function(key, value) {
+      return this._object[key] = value;
+    },
+
+    get: function(key) {
+      return this._object[key];
+    },
+
+    unset: function(key) {
+      var value = this._object[key];
+      delete this._object[key];
+      return value;
+    },
+
+    toObject: function() {
+      return Object.clone(this._object);
+    },
+
+    keys: function() {
+      return this.pluck('key');
+    },
+
+    values: function() {
+      return this.pluck('value');
+    },
+
+    index: function(value) {
+      var match = this.detect(function(pair) {
+        return pair.value === value;
+      });
+      return match && match.key;
+    },
+
+    merge: function(object) {
+      return this.clone().update(object);
+    },
+
+    update: function(object) {
+      return new Hash(object).inject(this, function(result, pair) {
+        result.set(pair.key, pair.value);
+        return result;
+      });
+    },
+
+    toQueryString: function() {
+      return this.map(function(pair) {
+        var key = encodeURIComponent(pair.key), values = pair.value;
+
+        if (values && typeof values == 'object') {
+          if (Object.isArray(values))
+            return values.map(toQueryPair.curry(key)).join('&');
+        }
+        return toQueryPair(key, values);
+      }).join('&');
+    },
+
+    inspect: function() {
+      return '#<Hash:{' + this.map(function(pair) {
+        return pair.map(Object.inspect).join(': ');
+      }).join(', ') + '}>';
+    },
+
+    toJSON: function() {
+      return Object.toJSON(this.toObject());
+    },
+
+    clone: function() {
+      return new Hash(this);
+    }
+  }
+})());
+
+Hash.prototype.toTemplateReplacements = Hash.prototype.toObject;
+Hash.from = $H;
+var ObjectRange = Class.create(Enumerable, {
+  initialize: function(start, end, exclusive) {
+    this.start = start;
+    this.end = end;
+    this.exclusive = exclusive;
+  },
+
+  _each: function(iterator) {
+    var value = this.start;
+    while (this.include(value)) {
+      iterator(value);
+      value = value.succ();
+    }
+  },
+
+  include: function(value) {
+    if (value < this.start)
+      return false;
+    if (this.exclusive)
+      return value < this.end;
+    return value <= this.end;
+  }
+});
+
+var $R = function(start, end, exclusive) {
+  return new ObjectRange(start, end, exclusive);
+};
+
+var Ajax = {
+  getTransport: function() {
+    return Try.these(
+      function() {return new XMLHttpRequest()},
+      function() {return new ActiveXObject('Msxml2.XMLHTTP')},
+      function() {return new ActiveXObject('Microsoft.XMLHTTP')}
+    ) || false;
+  },
+
+  activeRequestCount: 0
+};
+
+Ajax.Responders = {
+  responders: [],
+
+  _each: function(iterator) {
+    this.responders._each(iterator);
+  },
+
+  register: function(responder) {
+    if (!this.include(responder))
+      this.responders.push(responder);
+  },
+
+  unregister: function(responder) {
+    this.responders = this.responders.without(responder);
+  },
+
+  dispatch: function(callback, request, transport, json) {
+    this.each(function(responder) {
+      if (Object.isFunction(responder[callback])) {
+        try {
+          responder[callback].apply(responder, [request, transport, json]);
+        } catch (e) { }
+      }
+    });
+  }
+};
+
+Object.extend(Ajax.Responders, Enumerable);
+
+Ajax.Responders.register({
+  onCreate:   function() { Ajax.activeRequestCount++ },
+  onComplete: function() { Ajax.activeRequestCount-- }
+});
+
+Ajax.Base = Class.create({
+  initialize: function(options) {
+    this.options = {
+      method:       'post',
+      asynchronous: true,
+      contentType:  'application/x-www-form-urlencoded',
+      encoding:     'UTF-8',
+      parameters:   '',
+      evalJSON:     true,
+      evalJS:       true
+    };
+    Object.extend(this.options, options || { });
+
+    this.options.method = this.options.method.toLowerCase();
+    if (Object.isString(this.options.parameters))
+      this.options.parameters = this.options.parameters.toQueryParams();
+  }
+});
+
+Ajax.Request = Class.create(Ajax.Base, {
+  _complete: false,
+
+  initialize: function($super, url, options) {
+    $super(options);
+    this.transport = Ajax.getTransport();
+    this.request(url);
+  },
+
+  request: function(url) {
+    this.url = url;
+    this.method = this.options.method;
+    var params = Object.clone(this.options.parameters);
+
+    if (!['get', 'post'].include(this.method)) {
+      // simulate other verbs over post
+      params['_method'] = this.method;
+      this.method = 'post';
+    }
+
+    this.parameters = params;
+
+    if (params = Object.toQueryString(params)) {
+      // when GET, append parameters to URL
+      if (this.method == 'get')
+        this.url += (this.url.include('?') ? '&' : '?') + params;
+      else if (/Konqueror|Safari|KHTML/.test(navigator.userAgent))
+        params += '&_=';
+    }
+
+    try {
+      var response = new Ajax.Response(this);
+      if (this.options.onCreate) this.options.onCreate(response);
+      Ajax.Responders.dispatch('onCreate', this, response);
+
+      this.transport.open(this.method.toUpperCase(), this.url,
+        this.options.asynchronous);
+
+      if (this.options.asynchronous) this.respondToReadyState.bind(this).defer(1);
+
+      this.transport.onreadystatechange = this.onStateChange.bind(this);
+      this.setRequestHeaders();
+
+      this.body = this.method == 'post' ? (this.options.postBody || params) : null;
+      this.transport.send(this.body);
+
+      /* Force Firefox to handle ready state 4 for synchronous requests */
+      if (!this.options.asynchronous && this.transport.overrideMimeType)
+        this.onStateChange();
+
+    }
+    catch (e) {
+      this.dispatchException(e);
+    }
+  },
+
+  onStateChange: function() {
+    var readyState = this.transport.readyState;
+    if (readyState > 1 && !((readyState == 4) && this._complete))
+      this.respondToReadyState(this.transport.readyState);
+  },
+
+  setRequestHeaders: function() {
+    var headers = {
+      'X-Requested-With': 'XMLHttpRequest',
+      'X-Prototype-Version': Prototype.Version,
+      'Accept': 'text/javascript, text/html, application/xml, text/xml, */*'
+    };
+
+    if (this.method == 'post') {
+      headers['Content-type'] = this.options.contentType +
+        (this.options.encoding ? '; charset=' + this.options.encoding : '');
+
+      /* Force "Connection: close" for older Mozilla browsers to work
+       * around a bug where XMLHttpRequest sends an incorrect
+       * Content-length header. See Mozilla Bugzilla #246651.
+       */
+      if (this.transport.overrideMimeType &&
+          (navigator.userAgent.match(/Gecko\/(\d{4})/) || [0,2005])[1] < 2005)
+            headers['Connection'] = 'close';
+    }
+
+    // user-defined headers
+    if (typeof this.options.requestHeaders == 'object') {
+      var extras = this.options.requestHeaders;
+
+      if (Object.isFunction(extras.push))
+        for (var i = 0, length = extras.length; i < length; i += 2)
+          headers[extras[i]] = extras[i+1];
+      else
+        $H(extras).each(function(pair) { headers[pair.key] = pair.value });
+    }
+
+    for (var name in headers)
+      this.transport.setRequestHeader(name, headers[name]);
+  },
+
+  success: function() {
+    var status = this.getStatus();
+    return !status || (status >= 200 && status < 300);
+  },
+
+  getStatus: function() {
+    try {
+      return this.transport.status || 0;
+    } catch (e) { return 0 }
+  },
+
+  respondToReadyState: function(readyState) {
+    var state = Ajax.Request.Events[readyState], response = new Ajax.Response(this);
+
+    if (state == 'Complete') {
+      try {
+        this._complete = true;
+        (this.options['on' + response.status]
+         || this.options['on' + (this.success() ? 'Success' : 'Failure')]
+         || Prototype.emptyFunction)(response, response.headerJSON);
+      } catch (e) {
+        this.dispatchException(e);
+      }
+
+      var contentType = response.getHeader('Content-type');
+      if (this.options.evalJS == 'force'
+          || (this.options.evalJS && contentType
+          && contentType.match(/^\s*(text|application)\/(x-)?(java|ecma)script(;.*)?\s*$/i)))
+        this.evalResponse();
+    }
+
+    try {
+      (this.options['on' + state] || Prototype.emptyFunction)(response, response.headerJSON);
+      Ajax.Responders.dispatch('on' + state, this, response, response.headerJSON);
+    } catch (e) {
+      this.dispatchException(e);
+    }
+
+    if (state == 'Complete') {
+      // avoid memory leak in MSIE: clean up
+      this.transport.onreadystatechange = Prototype.emptyFunction;
+    }
+  },
+
+  getHeader: function(name) {
+    try {
+      return this.transport.getResponseHeader(name);
+    } catch (e) { return null }
+  },
+
+  evalResponse: function() {
+    try {
+      return eval((this.transport.responseText || '').unfilterJSON());
+    } catch (e) {
+      this.dispatchException(e);
+    }
+  },
+
+  dispatchException: function(exception) {
+    (this.options.onException || Prototype.emptyFunction)(this, exception);
+    Ajax.Responders.dispatch('onException', this, exception);
+  }
+});
+
+Ajax.Request.Events =
+  ['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];
+
+Ajax.Response = Class.create({
+  initialize: function(request){
+    this.request = request;
+    var transport  = this.transport  = request.transport,
+        readyState = this.readyState = transport.readyState;
+
+    if((readyState > 2 && !Prototype.Browser.IE) || readyState == 4) {
+      this.status       = this.getStatus();
+      this.statusText   = this.getStatusText();
+      this.responseText = String.interpret(transport.responseText);
+      this.headerJSON   = this._getHeaderJSON();
+    }
+
+    if(readyState == 4) {
+      var xml = transport.responseXML;
+      this.responseXML  = xml === undefined ? null : xml;
+      this.responseJSON = this._getResponseJSON();
+    }
+  },
+
+  status:      0,
+  statusText: '',
+
+  getStatus: Ajax.Request.prototype.getStatus,
+
+  getStatusText: function() {
+    try {
+      return this.transport.statusText || '';
+    } catch (e) { return '' }
+  },
+
+  getHeader: Ajax.Request.prototype.getHeader,
+
+  getAllHeaders: function() {
+    try {
+      return this.getAllResponseHeaders();
+    } catch (e) { return null }
+  },
+
+  getResponseHeader: function(name) {
+    return this.transport.getResponseHeader(name);
+  },
+
+  getAllResponseHeaders: function() {
+    return this.transport.getAllResponseHeaders();
+  },
+
+  _getHeaderJSON: function() {
+    var json = this.getHeader('X-JSON');
+    if (!json) return null;
+    json = decodeURIComponent(escape(json));
+    try {
+      return json.evalJSON(this.request.options.sanitizeJSON);
+    } catch (e) {
+      this.request.dispatchException(e);
+    }
+  },
+
+  _getResponseJSON: function() {
+    var options = this.request.options;
+    if (!options.evalJSON || (options.evalJSON != 'force' &&
+      !(this.getHeader('Content-type') || '').include('application/json')))
+        return null;
+    try {
+      return this.transport.responseText.evalJSON(options.sanitizeJSON);
+    } catch (e) {
+      this.request.dispatchException(e);
+    }
+  }
+});
+
+Ajax.Updater = Class.create(Ajax.Request, {
+  initialize: function($super, container, url, options) {
+    this.container = {
+      success: (container.success || container),
+      failure: (container.failure || (container.success ? null : container))
+    };
+
+    options = options || { };
+    var onComplete = options.onComplete;
+    options.onComplete = (function(response, param) {
+      this.updateContent(response.responseText);
+      if (Object.isFunction(onComplete)) onComplete(response, param);
+    }).bind(this);
+
+    $super(url, options);
+  },
+
+  updateContent: function(responseText) {
+    var receiver = this.container[this.success() ? 'success' : 'failure'],
+        options = this.options;
+
+    if (!options.evalScripts) responseText = responseText.stripScripts();
+
+    if (receiver = $(receiver)) {
+      if (options.insertion) {
+        if (Object.isString(options.insertion)) {
+          var insertion = { }; insertion[options.insertion] = responseText;
+          receiver.insert(insertion);
+        }
+        else options.insertion(receiver, responseText);
+      }
+      else receiver.update(responseText);
+    }
+
+    if (this.success()) {
+      if (this.onComplete) this.onComplete.bind(this).defer();
+    }
+  }
+});
+
+Ajax.PeriodicalUpdater = Class.create(Ajax.Base, {
+  initialize: function($super, container, url, options) {
+    $super(options);
+    this.onComplete = this.options.onComplete;
+
+    this.frequency = (this.options.frequency || 2);
+    this.decay = (this.options.decay || 1);
+
+    this.updater = { };
+    this.container = container;
+    this.url = url;
+
+    this.start();
+  },
+
+  start: function() {
+    this.options.onComplete = this.updateComplete.bind(this);
+    this.onTimerEvent();
+  },
+
+  stop: function() {
+    this.updater.options.onComplete = undefined;
+    clearTimeout(this.timer);
+    (this.onComplete || Prototype.emptyFunction).apply(this, arguments);
+  },
+
+  updateComplete: function(response) {
+    if (this.options.decay) {
+      this.decay = (response.responseText == this.lastText ?
+        this.decay * this.options.decay : 1);
+
+      this.lastText = response.responseText;
+    }
+    this.timer = this.onTimerEvent.bind(this).delay(this.decay * this.frequency);
+  },
+
+  onTimerEvent: function() {
+    this.updater = new Ajax.Updater(this.container, this.url, this.options);
+  }
+});
+function $(element) {
+  if (arguments.length > 1) {
+    for (var i = 0, elements = [], length = arguments.length; i < length; i++)
+      elements.push($(arguments[i]));
+    return elements;
+  }
+  if (Object.isString(element))
+    element = document.getElementById(element);
+  return Element.extend(element);
+}
+
+if (Prototype.BrowserFeatures.XPath) {
+  document._getElementsByXPath = function(expression, parentElement) {
+    var results = [];
+    var query = document.evaluate(expression, $(parentElement) || document,
+      null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
+    for (var i = 0, length = query.snapshotLength; i < length; i++)
+      results.push(Element.extend(query.snapshotItem(i)));
+    return results;
+  };
+}
+
+/*--------------------------------------------------------------------------*/
+
+if (!window.Node) var Node = { };
+
+if (!Node.ELEMENT_NODE) {
+  // DOM level 2 ECMAScript Language Binding
+  Object.extend(Node, {
+    ELEMENT_NODE: 1,
+    ATTRIBUTE_NODE: 2,
+    TEXT_NODE: 3,
+    CDATA_SECTION_NODE: 4,
+    ENTITY_REFERENCE_NODE: 5,
+    ENTITY_NODE: 6,
+    PROCESSING_INSTRUCTION_NODE: 7,
+    COMMENT_NODE: 8,
+    DOCUMENT_NODE: 9,
+    DOCUMENT_TYPE_NODE: 10,
+    DOCUMENT_FRAGMENT_NODE: 11,
+    NOTATION_NODE: 12
+  });
+}
+
+(function() {
+  var element = this.Element;
+  this.Element = function(tagName, attributes) {
+    attributes = attributes || { };
+    tagName = tagName.toLowerCase();
+    var cache = Element.cache;
+    if (Prototype.Browser.IE && attributes.name) {
+      tagName = '<' + tagName + ' name="' + attributes.name + '">';
+      delete attributes.name;
+      return Element.writeAttribute(document.createElement(tagName), attributes);
+    }
+    if (!cache[tagName]) cache[tagName] = Element.extend(document.createElement(tagName));
+    return Element.writeAttribute(cache[tagName].cloneNode(false), attributes);
+  };
+  Object.extend(this.Element, element || { });
+}).call(window);
+
+Element.cache = { };
+
+Element.Methods = {
+  visible: function(element) {
+    return $(element).style.display != 'none';
+  },
+
+  toggle: function(element) {
+    element = $(element);
+    Element[Element.visible(element) ? 'hide' : 'show'](element);
+    return element;
+  },
+
+  hide: function(element) {
+    $(element).style.display = 'none';
+    return element;
+  },
+
+  show: function(element) {
+    $(element).style.display = '';
+    return element;
+  },
+
+  remove: function(element) {
+    element = $(element);
+    element.parentNode.removeChild(element);
+    return element;
+  },
+
+  update: function(element, content) {
+    element = $(element);
+    if (content && content.toElement) content = content.toElement();
+    if (Object.isElement(content)) return element.update().insert(content);
+    content = Object.toHTML(content);
+    element.innerHTML = content.stripScripts();
+    content.evalScripts.bind(content).defer();
+    return element;
+  },
+
+  replace: function(element, content) {
+    element = $(element);
+    if (content && content.toElement) content = content.toElement();
+    else if (!Object.isElement(content)) {
+      content = Object.toHTML(content);
+      var range = element.ownerDocument.createRange();
+      range.selectNode(element);
+      content.evalScripts.bind(content).defer();
+      content = range.createContextualFragment(content.stripScripts());
+    }
+    element.parentNode.replaceChild(content, element);
+    return element;
+  },
+
+  insert: function(element, insertions) {
+    element = $(element);
+
+    if (Object.isString(insertions) || Object.isNumber(insertions) ||
+        Object.isElement(insertions) || (insertions && (insertions.toElement || insertions.toHTML)))
+          insertions = {bottom:insertions};
+
+    var content, t, range;
+
+    for (position in insertions) {
+      content  = insertions[position];
+      position = position.toLowerCase();
+      t = Element._insertionTranslations[position];
+
+      if (content && content.toElement) content = content.toElement();
+      if (Object.isElement(content)) {
+        t.insert(element, content);
+        continue;
+      }
+
+      content = Object.toHTML(content);
+
+      range = element.ownerDocument.createRange();
+      t.initializeRange(element, range);
+      t.insert(element, range.createContextualFragment(content.stripScripts()));
+
+      content.evalScripts.bind(content).defer();
+    }
+
+    return element;
+  },
+
+  wrap: function(element, wrapper, attributes) {
+    element = $(element);
+    if (Object.isElement(wrapper))
+      $(wrapper).writeAttribute(attributes || { });
+    else if (Object.isString(wrapper)) wrapper = new Element(wrapper, attributes);
+    else wrapper = new Element('div', wrapper);
+    if (element.parentNode)
+      element.parentNode.replaceChild(wrapper, element);
+    wrapper.appendChild(element);
+    return wrapper;
+  },
+
+  inspect: function(element) {
+    element = $(element);
+    var result = '<' + element.tagName.toLowerCase();
+    $H({'id': 'id', 'className': 'class'}).each(function(pair) {
+      var property = pair.first(), attribute = pair.last();
+      var value = (element[property] || '').toString();
+      if (value) result += ' ' + attribute + '=' + value.inspect(true);
+    });
+    return result + '>';
+  },
+
+  recursivelyCollect: function(element, property) {
+    element = $(element);
+    var elements = [];
+    while (element = element[property])
+      if (element.nodeType == 1)
+        elements.push(Element.extend(element));
+    return elements;
+  },
+
+  ancestors: function(element) {
+    return $(element).recursivelyCollect('parentNode');
+  },
+
+  descendants: function(element) {
+    return $A($(element).getElementsByTagName('*')).each(Element.extend);
+  },
+
+  firstDescendant: function(element) {
+    element = $(element).firstChild;
+    while (element && element.nodeType != 1) element = element.nextSibling;
+    return $(element);
+  },
+
+  immediateDescendants: function(element) {
+    if (!(element = $(element).firstChild)) return [];
+    while (element && element.nodeType != 1) element = element.nextSibling;
+    if (element) return [element].concat($(element).nextSiblings());
+    return [];
+  },
+
+  previousSiblings: function(element) {
+    return $(element).recursivelyCollect('previousSibling');
+  },
+
+  nextSiblings: function(element) {
+    return $(element).recursivelyCollect('nextSibling');
+  },
+
+  siblings: function(element) {
+    element = $(element);
+    return element.previousSiblings().reverse().concat(element.nextSiblings());
+  },
+
+  match: function(element, selector) {
+    if (Object.isString(selector))
+      selector = new Selector(selector);
+    return selector.match($(element));
+  },
+
+  up: function(element, expression, index) {
+    element = $(element);
+    if (arguments.length == 1) return $(element.parentNode);
+    var ancestors = element.ancestors();
+    return expression ? Selector.findElement(ancestors, expression, index) :
+      ancestors[index || 0];
+  },
+
+  down: function(element, expression, index) {
+    element = $(element);
+    if (arguments.length == 1) return element.firstDescendant();
+    var descendants = element.descendants();
+    return expression ? Selector.findElement(descendants, expression, index) :
+      descendants[index || 0];
+  },
+
+  previous: function(element, expression, index) {
+    element = $(element);
+    if (arguments.length == 1) return $(Selector.handlers.previousElementSibling(element));
+    var previousSiblings = element.previousSiblings();
+    return expression ? Selector.findElement(previousSiblings, expression, index) :
+      previousSiblings[index || 0];
+  },
+
+  next: function(element, expression, index) {
+    element = $(element);
+    if (arguments.length == 1) return $(Selector.handlers.nextElementSibling(element));
+    var nextSiblings = element.nextSiblings();
+    return expression ? Selector.findElement(nextSiblings, expression, index) :
+      nextSiblings[index || 0];
+  },
+
+  select: function() {
+    var args = $A(arguments), element = $(args.shift());
+    return Selector.findChildElements(element, args);
+  },
+
+  adjacent: function() {
+    var args = $A(arguments), element = $(args.shift());
+    return Selector.findChildElements(element.parentNode, args).without(element);
+  },
+
+  identify: function(element) {
+    element = $(element);
+    var id = element.readAttribute('id'), self = arguments.callee;
+    if (id) return id;
+    do { id = 'anonymous_element_' + self.counter++ } while ($(id));
+    element.writeAttribute('id', id);
+    return id;
+  },
+
+  readAttribute: function(element, name) {
+    element = $(element);
+    if (Prototype.Browser.IE) {
+      var t = Element._attributeTranslations.read;
+      if (t.values[name]) return t.values[name](element, name);
+      if (t.names[name]) name = t.names[name];
+      if (name.include(':')) {
+        return (!element.attributes || !element.attributes[name]) ? null :
+         element.attributes[name].value;
+      }
+    }
+    return element.getAttribute(name);
+  },
+
+  writeAttribute: function(element, name, value) {
+    element = $(element);
+    var attributes = { }, t = Element._attributeTranslations.write;
+
+    if (typeof name == 'object') attributes = name;
+    else attributes[name] = value === undefined ? true : value;
+
+    for (var attr in attributes) {
+      var name = t.names[attr] || attr, value = attributes[attr];
+      if (t.values[attr]) name = t.values[attr](element, value);
+      if (value === false || value === null)
+        element.removeAttribute(name);
+      else if (value === true)
+        element.setAttribute(name, name);
+      else element.setAttribute(name, value);
+    }
+    return element;
+  },
+
+  getHeight: function(element) {
+    return $(element).getDimensions().height;
+  },
+
+  getWidth: function(element) {
+    return $(element).getDimensions().width;
+  },
+
+  classNames: function(element) {
+    return new Element.ClassNames(element);
+  },
+
+  hasClassName: function(element, className) {
+    if (!(element = $(element))) return;
+    var elementClassName = element.className;
+    return (elementClassName.length > 0 && (elementClassName == className ||
+      new RegExp("(^|\\s)" + className + "(\\s|$)").test(elementClassName)));
+  },
+
+  addClassName: function(element, className) {
+    if (!(element = $(element))) return;
+    if (!element.hasClassName(className))
+      element.className += (element.className ? ' ' : '') + className;
+    return element;
+  },
+
+  removeClassName: function(element, className) {
+    if (!(element = $(element))) return;
+    element.className = element.className.replace(
+      new RegExp("(^|\\s+)" + className + "(\\s+|$)"), ' ').strip();
+    return element;
+  },
+
+  toggleClassName: function(element, className) {
+    if (!(element = $(element))) return;
+    return element[element.hasClassName(className) ?
+      'removeClassName' : 'addClassName'](className);
+  },
+
+  // removes whitespace-only text node children
+  cleanWhitespace: function(element) {
+    element = $(element);
+    var node = element.firstChild;
+    while (node) {
+      var nextNode = node.nextSibling;
+      if (node.nodeType == 3 && !/\S/.test(node.nodeValue))
+        element.removeChild(node);
+      node = nextNode;
+    }
+    return element;
+  },
+
+  empty: function(element) {
+    return $(element).innerHTML.blank();
+  },
+
+  descendantOf: function(element, ancestor) {
+    element = $(element), ancestor = $(ancestor);
+
+    if (element.compareDocumentPosition)
+      return (element.compareDocumentPosition(ancestor) & 8) === 8;
+
+    if (element.sourceIndex && !Prototype.Browser.Opera) {
+      var e = element.sourceIndex, a = ancestor.sourceIndex,
+       nextAncestor = ancestor.nextSibling;
+      if (!nextAncestor) {
+        do { ancestor = ancestor.parentNode; }
+        while (!(nextAncestor = ancestor.nextSibling) && ancestor.parentNode);
+      }
+      if (nextAncestor) return (e > a && e < nextAncestor.sourceIndex);
+    }
+
+    while (element = element.parentNode)
+      if (element == ancestor) return true;
+    return false;
+  },
+
+  scrollTo: function(element) {
+    element = $(element);
+    var pos = element.cumulativeOffset();
+    window.scrollTo(pos[0], pos[1]);
+    return element;
+  },
+
+  getStyle: function(element, style) {
+    element = $(element);
+    style = style == 'float' ? 'cssFloat' : style.camelize();
+    var value = element.style[style];
+    if (!value) {
+      var css = document.defaultView.getComputedStyle(element, null);
+      value = css ? css[style] : null;
+    }
+    if (style == 'opacity') return value ? parseFloat(value) : 1.0;
+    return value == 'auto' ? null : value;
+  },
+
+  getOpacity: function(element) {
+    return $(element).getStyle('opacity');
+  },
+
+  setStyle: function(element, styles) {
+    element = $(element);
+    var elementStyle = element.style, match;
+    if (Object.isString(styles)) {
+      element.style.cssText += ';' + styles;
+      return styles.include('opacity') ?
+        element.setOpacity(styles.match(/opacity:\s*(\d?\.?\d*)/)[1]) : element;
+    }
+    for (var property in styles)
+      if (property == 'opacity') element.setOpacity(styles[property]);
+      else
+        elementStyle[(property == 'float' || property == 'cssFloat') ?
+          (elementStyle.styleFloat === undefined ? 'cssFloat' : 'styleFloat') :
+            property] = styles[property];
+
+    return element;
+  },
+
+  setOpacity: function(element, value) {
+    element = $(element);
+    element.style.opacity = (value == 1 || value === '') ? '' :
+      (value < 0.00001) ? 0 : value;
+    return element;
+  },
+
+  getDimensions: function(element) {
+    element = $(element);
+    var display = $(element).getStyle('display');
+    if (display != 'none' && display != null) // Safari bug
+      return {width: element.offsetWidth, height: element.offsetHeight};
+
+    // All *Width and *Height properties give 0 on elements with display none,
+    // so enable the element temporarily
+    var els = element.style;
+    var originalVisibility = els.visibility;
+    var originalPosition = els.position;
+    var originalDisplay = els.display;
+    els.visibility = 'hidden';
+    els.position = 'absolute';
+    els.display = 'block';
+    var originalWidth = element.clientWidth;
+    var originalHeight = element.clientHeight;
+    els.display = originalDisplay;
+    els.position = originalPosition;
+    els.visibility = originalVisibility;
+    return {width: originalWidth, height: originalHeight};
+  },
+
+  makePositioned: function(element) {
+    element = $(element);
+    var pos = Element.getStyle(element, 'position');
+    if (pos == 'static' || !pos) {
+      element._madePositioned = true;
+      element.style.position = 'relative';
+      // Opera returns the offset relative to the positioning context, when an
+      // element is position relative but top and left have not been defined
+      if (window.opera) {
+        element.style.top = 0;
+        element.style.left = 0;
+      }
+    }
+    return element;
+  },
+
+  undoPositioned: function(element) {
+    element = $(element);
+    if (element._madePositioned) {
+      element._madePositioned = undefined;
+      element.style.position =
+        element.style.top =
+        element.style.left =
+        element.style.bottom =
+        element.style.right = '';
+    }
+    return element;
+  },
+
+  makeClipping: function(element) {
+    element = $(element);
+    if (element._overflow) return element;
+    element._overflow = Element.getStyle(element, 'overflow') || 'auto';
+    if (element._overflow !== 'hidden')
+      element.style.overflow = 'hidden';
+    return element;
+  },
+
+  undoClipping: function(element) {
+    element = $(element);
+    if (!element._overflow) return element;
+    element.style.overflow = element._overflow == 'auto' ? '' : element._overflow;
+    element._overflow = null;
+    return element;
+  },
+
+  cumulativeOffset: function(element) {
+    var valueT = 0, valueL = 0;
+    do {
+      valueT += element.offsetTop  || 0;
+      valueL += element.offsetLeft || 0;
+      element = element.offsetParent;
+    } while (element);
+    return Element._returnOffset(valueL, valueT);
+  },
+
+  positionedOffset: function(element) {
+    var valueT = 0, valueL = 0;
+    do {
+      valueT += element.offsetTop  || 0;
+      valueL += element.offsetLeft || 0;
+      element = element.offsetParent;
+      if (element) {
+        if (element.tagName == 'BODY') break;
+        var p = Element.getStyle(element, 'position');
+        if (p == 'relative' || p == 'absolute') break;
+      }
+    } while (element);
+    return Element._returnOffset(valueL, valueT);
+  },
+
+  absolutize: function(element) {
+    element = $(element);
+    if (element.getStyle('position') == 'absolute') return;
+    // Position.prepare(); // To be done manually by Scripty when it needs it.
+
+    var offsets = element.positionedOffset();
+    var top     = offsets[1];
+    var left    = offsets[0];
+    var width   = element.clientWidth;
+    var height  = element.clientHeight;
+
+    element._originalLeft   = left - parseFloat(element.style.left  || 0);
+    element._originalTop    = top  - parseFloat(element.style.top || 0);
+    element._originalWidth  = element.style.width;
+    element._originalHeight = element.style.height;
+
+    element.style.position = 'absolute';
+    element.style.top    = top + 'px';
+    element.style.left   = left + 'px';
+    element.style.width  = width + 'px';
+    element.style.height = height + 'px';
+    return element;
+  },
+
+  relativize: function(element) {
+    element = $(element);
+    if (element.getStyle('position') == 'relative') return;
+    // Position.prepare(); // To be done manually by Scripty when it needs it.
+
+    element.style.position = 'relative';
+    var top  = parseFloat(element.style.top  || 0) - (element._originalTop || 0);
+    var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);
+
+    element.style.top    = top + 'px';
+    element.style.left   = left + 'px';
+    element.style.height = element._originalHeight;
+    element.style.width  = element._originalWidth;
+    return element;
+  },
+
+  cumulativeScrollOffset: function(element) {
+    var valueT = 0, valueL = 0;
+    do {
+      valueT += element.scrollTop  || 0;
+      valueL += element.scrollLeft || 0;
+      element = element.parentNode;
+    } while (element);
+    return Element._returnOffset(valueL, valueT);
+  },
+
+  getOffsetParent: function(element) {
+    if (element.offsetParent) return $(element.offsetParent);
+    if (element == document.body) return $(element);
+
+    while ((element = element.parentNode) && element != document.body)
+      if (Element.getStyle(element, 'position') != 'static')
+        return $(element);
+
+    return $(document.body);
+  },
+
+  viewportOffset: function(forElement) {
+    var valueT = 0, valueL = 0;
+
+    var element = forElement;
+    do {
+      valueT += element.offsetTop  || 0;
+      valueL += element.offsetLeft || 0;
+
+      // Safari fix
+      if (element.offsetParent == document.body &&
+        Element.getStyle(element, 'position') == 'absolute') break;
+
+    } while (element = element.offsetParent);
+
+    element = forElement;
+    do {
+      if (!Prototype.Browser.Opera || element.tagName == 'BODY') {
+        valueT -= element.scrollTop  || 0;
+        valueL -= element.scrollLeft || 0;
+      }
+    } while (element = element.parentNode);
+
+    return Element._returnOffset(valueL, valueT);
+  },
+
+  clonePosition: function(element, source) {
+    var options = Object.extend({
+      setLeft:    true,
+      setTop:     true,
+      setWidth:   true,
+      setHeight:  true,
+      offsetTop:  0,
+      offsetLeft: 0
+    }, arguments[2] || { });
+
+    // find page position of source
+    source = $(source);
+    var p = source.viewportOffset();
+
+    // find coordinate system to use
+    element = $(element);
+    var delta = [0, 0];
+    var parent = null;
+    // delta [0,0] will do fine with position: fixed elements,
+    // position:absolute needs offsetParent deltas
+    if (Element.getStyle(element, 'position') == 'absolute') {
+      parent = element.getOffsetParent();
+      delta = parent.viewportOffset();
+    }
+
+    // correct by body offsets (fixes Safari)
+    if (parent == document.body) {
+      delta[0] -= document.body.offsetLeft;
+      delta[1] -= document.body.offsetTop;
+    }
+
+    // set position
+    if (options.setLeft)   element.style.left  = (p[0] - delta[0] + options.offsetLeft) + 'px';
+    if (options.setTop)    element.style.top   = (p[1] - delta[1] + options.offsetTop) + 'px';
+    if (options.setWidth)  element.style.width = source.offsetWidth + 'px';
+    if (options.setHeight) element.style.height = source.offsetHeight + 'px';
+    return element;
+  }
+};
+
+Element.Methods.identify.counter = 1;
+
+Object.extend(Element.Methods, {
+  getElementsBySelector: Element.Methods.select,
+  childElements: Element.Methods.immediateDescendants
+});
+
+Element._attributeTranslations = {
+  write: {
+    names: {
+      className: 'class',
+      htmlFor:   'for'
+    },
+    values: { }
+  }
+};
+
+
+if (!document.createRange || Prototype.Browser.Opera) {
+  Element.Methods.insert = function(element, insertions) {
+    element = $(element);
+
+    if (Object.isString(insertions) || Object.isNumber(insertions) ||
+        Object.isElement(insertions) || (insertions && (insertions.toElement || insertions.toHTML)))
+          insertions = { bottom: insertions };
+
+    var t = Element._insertionTranslations, content, position, pos, tagName;
+
+    for (position in insertions) {
+      content  = insertions[position];
+      position = position.toLowerCase();
+      pos      = t[position];
+
+      if (content && content.toElement) content = content.toElement();
+      if (Object.isElement(content)) {
+        pos.insert(element, content);
+        continue;
+      }
+
+      content = Object.toHTML(content);
+      tagName = ((position == 'before' || position == 'after')
+        ? element.parentNode : element).tagName.toUpperCase();
+
+      if (t.tags[tagName]) {
+        var fragments = Element._getContentFromAnonymousElement(tagName, content.stripScripts());
+        if (position == 'top' || position == 'after') fragments.reverse();
+        fragments.each(pos.insert.curry(element));
+      }
+      else element.insertAdjacentHTML(pos.adjacency, content.stripScripts());
+
+      content.evalScripts.bind(content).defer();
+    }
+
+    return element;
+  };
+}
+
+if (Prototype.Browser.Opera) {
+  Element.Methods._getStyle = Element.Methods.getStyle;
+  Element.Methods.getStyle = function(element, style) {
+    switch(style) {
+      case 'left':
+      case 'top':
+      case 'right':
+      case 'bottom':
+        if (Element._getStyle(element, 'position') == 'static') return null;
+      default: return Element._getStyle(element, style);
+    }
+  };
+  Element.Methods._readAttribute = Element.Methods.readAttribute;
+  Element.Methods.readAttribute = function(element, attribute) {
+    if (attribute == 'title') return element.title;
+    return Element._readAttribute(element, attribute);
+  };
+}
+
+else if (Prototype.Browser.IE) {
+  $w('positionedOffset getOffsetParent viewportOffset').each(function(method) {
+    Element.Methods[method] = Element.Methods[method].wrap(
+      function(proceed, element) {
+        element = $(element);
+        var position = element.getStyle('position');
+        if (position != 'static') return proceed(element);
+        element.setStyle({ position: 'relative' });
+        var value = proceed(element);
+        element.setStyle({ position: position });
+        return value;
+      }
+    );
+  });
+
+  Element.Methods.getStyle = function(element, style) {
+    element = $(element);
+    style = (style == 'float' || style == 'cssFloat') ? 'styleFloat' : style.camelize();
+    var value = element.style[style];
+    if (!value && element.currentStyle) value = element.currentStyle[style];
+
+    if (style == 'opacity') {
+      if (value = (element.getStyle('filter') || '').match(/alpha\(opacity=(.*)\)/))
+        if (value[1]) return parseFloat(value[1]) / 100;
+      return 1.0;
+    }
+
+    if (value == 'auto') {
+      if ((style == 'width' || style == 'height') && (element.getStyle('display') != 'none'))
+        return element['offset' + style.capitalize()] + 'px';
+      return null;
+    }
+    return value;
+  };
+
+  Element.Methods.setOpacity = function(element, value) {
+    function stripAlpha(filter){
+      return filter.replace(/alpha\([^\)]*\)/gi,'');
+    }
+    element = $(element);
+    var currentStyle = element.currentStyle;
+    if ((currentStyle && !currentStyle.hasLayout) ||
+      (!currentStyle && element.style.zoom == 'normal'))
+        element.style.zoom = 1;
+
+    var filter = element.getStyle('filter'), style = element.style;
+    if (value == 1 || value === '') {
+      (filter = stripAlpha(filter)) ?
+        style.filter = filter : style.removeAttribute('filter');
+      return element;
+    } else if (value < 0.00001) value = 0;
+    style.filter = stripAlpha(filter) +
+      'alpha(opacity=' + (value * 100) + ')';
+    return element;
+  };
+
+  Element._attributeTranslations = {
+    read: {
+      names: {
+        'class': 'className',
+        'for':   'htmlFor'
+      },
+      values: {
+        _getAttr: function(element, attribute) {
+          return element.getAttribute(attribute, 2);
+        },
+        _getAttrNode: function(element, attribute) {
+          var node = element.getAttributeNode(attribute);
+          return node ? node.value : "";
+        },
+        _getEv: function(element, attribute) {
+          var attribute = element.getAttribute(attribute);
+          return attribute ? attribute.toString().slice(23, -2) : null;
+        },
+        _flag: function(element, attribute) {
+          return $(element).hasAttribute(attribute) ? attribute : null;
+        },
+        style: function(element) {
+          return element.style.cssText.toLowerCase();
+        },
+        title: function(element) {
+          return element.title;
+        }
+      }
+    }
+  };
+
+  Element._attributeTranslations.write = {
+    names: Object.clone(Element._attributeTranslations.read.names),
+    values: {
+      checked: function(element, value) {
+        element.checked = !!value;
+      },
+
+      style: function(element, value) {
+        element.style.cssText = value ? value : '';
+      }
+    }
+  };
+
+  Element._attributeTranslations.has = {};
+
+  $w('colSpan rowSpan vAlign dateTime accessKey tabIndex ' +
+      'encType maxLength readOnly longDesc').each(function(attr) {
+    Element._attributeTranslations.write.names[attr.toLowerCase()] = attr;
+    Element._attributeTranslations.has[attr.toLowerCase()] = attr;
+  });
+
+  (function(v) {
+    Object.extend(v, {
+      href:        v._getAttr,
+      src:         v._getAttr,
+      type:        v._getAttr,
+      action:      v._getAttrNode,
+      disabled:    v._flag,
+      checked:     v._flag,
+      readonly:    v._flag,
+      multiple:    v._flag,
+      onload:      v._getEv,
+      onunload:    v._getEv,
+      onclick:     v._getEv,
+      ondblclick:  v._getEv,
+      onmousedown: v._getEv,
+      onmouseup:   v._getEv,
+      onmouseover: v._getEv,
+      onmousemove: v._getEv,
+      onmouseout:  v._getEv,
+      onfocus:     v._getEv,
+      onblur:      v._getEv,
+      onkeypress:  v._getEv,
+      onkeydown:   v._getEv,
+      onkeyup:     v._getEv,
+      onsubmit:    v._getEv,
+      onreset:     v._getEv,
+      onselect:    v._getEv,
+      onchange:    v._getEv
+    });
+  })(Element._attributeTranslations.read.values);
+}
+
+else if (Prototype.Browser.Gecko && /rv:1\.8\.0/.test(navigator.userAgent)) {
+  Element.Methods.setOpacity = function(element, value) {
+    element = $(element);
+    element.style.opacity = (value == 1) ? 0.999999 :
+      (value === '') ? '' : (value < 0.00001) ? 0 : value;
+    return element;
+  };
+}
+
+else if (Prototype.Browser.WebKit) {
+  Element.Methods.setOpacity = function(element, value) {
+    element = $(element);
+    element.style.opacity = (value == 1 || value === '') ? '' :
+      (value < 0.00001) ? 0 : value;
+
+    if (value == 1)
+      if(element.tagName == 'IMG' && element.width) {
+        element.width++; element.width--;
+      } else try {
+        var n = document.createTextNode(' ');
+        element.appendChild(n);
+        element.removeChild(n);
+      } catch (e) { }
+
+    return element;
+  };
+
+  // Safari returns margins on body which is incorrect if the child is absolutely
+  // positioned.  For performance reasons, redefine Position.cumulativeOffset for
+  // KHTML/WebKit only.
+  Element.Methods.cumulativeOffset = function(element) {
+    var valueT = 0, valueL = 0;
+    do {
+      valueT += element.offsetTop  || 0;
+      valueL += element.offsetLeft || 0;
+      if (element.offsetParent == document.body)
+        if (Element.getStyle(element, 'position') == 'absolute') break;
+
+      element = element.offsetParent;
+    } while (element);
+
+    return Element._returnOffset(valueL, valueT);
+  };
+}
+
+if (Prototype.Browser.IE || Prototype.Browser.Opera) {
+  // IE and Opera are missing .innerHTML support for TABLE-related and SELECT elements
+  Element.Methods.update = function(element, content) {
+    element = $(element);
+
+    if (content && content.toElement) content = content.toElement();
+    if (Object.isElement(content)) return element.update().insert(content);
+
+    content = Object.toHTML(content);
+    var tagName = element.tagName.toUpperCase();
+
+    if (tagName in Element._insertionTranslations.tags) {
+      $A(element.childNodes).each(function(node) { element.removeChild(node) });
+      Element._getContentFromAnonymousElement(tagName, content.stripScripts())
+        .each(function(node) { element.appendChild(node) });
+    }
+    else element.innerHTML = content.stripScripts();
+
+    content.evalScripts.bind(content).defer();
+    return element;
+  };
+}
+
+if (document.createElement('div').outerHTML) {
+  Element.Methods.replace = function(element, content) {
+    element = $(element);
+
+    if (content && content.toElement) content = content.toElement();
+    if (Object.isElement(content)) {
+      element.parentNode.replaceChild(content, element);
+      return element;
+    }
+
+    content = Object.toHTML(content);
+    var parent = element.parentNode, tagName = parent.tagName.toUpperCase();
+
+    if (Element._insertionTranslations.tags[tagName]) {
+      var nextSibling = element.next();
+      var fragments = Element._getContentFromAnonymousElement(tagName, content.stripScripts());
+      parent.removeChild(element);
+      if (nextSibling)
+        fragments.each(function(node) { parent.insertBefore(node, nextSibling) });
+      else
+        fragments.each(function(node) { parent.appendChild(node) });
+    }
+    else element.outerHTML = content.stripScripts();
+
+    content.evalScripts.bind(content).defer();
+    return element;
+  };
+}
+
+Element._returnOffset = function(l, t) {
+  var result = [l, t];
+  result.left = l;
+  result.top = t;
+  return result;
+};
+
+Element._getContentFromAnonymousElement = function(tagName, html) {
+  var div = new Element('div'), t = Element._insertionTranslations.tags[tagName];
+  div.innerHTML = t[0] + html + t[1];
+  t[2].times(function() { div = div.firstChild });
+  return $A(div.childNodes);
+};
+
+Element._insertionTranslations = {
+  before: {
+    adjacency: 'beforeBegin',
+    insert: function(element, node) {
+      element.parentNode.insertBefore(node, element);
+    },
+    initializeRange: function(element, range) {
+      range.setStartBefore(element);
+    }
+  },
+  top: {
+    adjacency: 'afterBegin',
+    insert: function(element, node) {
+      element.insertBefore(node, element.firstChild);
+    },
+    initializeRange: function(element, range) {
+      range.selectNodeContents(element);
+      range.collapse(true);
+    }
+  },
+  bottom: {
+    adjacency: 'beforeEnd',
+    insert: function(element, node) {
+      element.appendChild(node);
+    }
+  },
+  after: {
+    adjacency: 'afterEnd',
+    insert: function(element, node) {
+      element.parentNode.insertBefore(node, element.nextSibling);
+    },
+    initializeRange: function(element, range) {
+      range.setStartAfter(element);
+    }
+  },
+  tags: {
+    TABLE:  ['<table>',                '</table>',                   1],
+    TBODY:  ['<table><tbody>',         '</tbody></table>',           2],
+    TR:     ['<table><tbody><tr>',     '</tr></tbody></table>',      3],
+    TD:     ['<table><tbody><tr><td>', '</td></tr></tbody></table>', 4],
+    SELECT: ['<select>',               '</select>',                  1]
+  }
+};
+
+(function() {
+  this.bottom.initializeRange = this.top.initializeRange;
+  Object.extend(this.tags, {
+    THEAD: this.tags.TBODY,
+    TFOOT: this.tags.TBODY,
+    TH:    this.tags.TD
+  });
+}).call(Element._insertionTranslations);
+
+Element.Methods.Simulated = {
+  hasAttribute: function(element, attribute) {
+    attribute = Element._attributeTranslations.has[attribute] || attribute;
+    var node = $(element).getAttributeNode(attribute);
+    return node && node.specified;
+  }
+};
+
+Element.Methods.ByTag = { };
+
+Object.extend(Element, Element.Methods);
+
+if (!Prototype.BrowserFeatures.ElementExtensions &&
+    document.createElement('div').__proto__) {
+  window.HTMLElement = { };
+  window.HTMLElement.prototype = document.createElement('div').__proto__;
+  Prototype.BrowserFeatures.ElementExtensions = true;
+}
+
+Element.extend = (function() {
+  if (Prototype.BrowserFeatures.SpecificElementExtensions)
+    return Prototype.K;
+
+  var Methods = { }, ByTag = Element.Methods.ByTag;
+
+  var extend = Object.extend(function(element) {
+    if (!element || element._extendedByPrototype ||
+        element.nodeType != 1 || element == window) return element;
+
+    var methods = Object.clone(Methods),
+      tagName = element.tagName, property, value;
+
+    // extend methods for specific tags
+    if (ByTag[tagName]) Object.extend(methods, ByTag[tagName]);
+
+    for (property in methods) {
+      value = methods[property];
+      if (Object.isFunction(value) && !(property in element))
+        element[property] = value.methodize();
+    }
+
+    element._extendedByPrototype = Prototype.emptyFunction;
+    return element;
+
+  }, {
+    refresh: function() {
+      // extend methods for all tags (Safari doesn't need this)
+      if (!Prototype.BrowserFeatures.ElementExtensions) {
+        Object.extend(Methods, Element.Methods);
+        Object.extend(Methods, Element.Methods.Simulated);
+      }
+    }
+  });
+
+  extend.refresh();
+  return extend;
+})();
+
+Element.hasAttribute = function(element, attribute) {
+  if (element.hasAttribute) return element.hasAttribute(attribute);
+  return Element.Methods.Simulated.hasAttribute(element, attribute);
+};
+
+Element.addMethods = function(methods) {
+  var F = Prototype.BrowserFeatures, T = Element.Methods.ByTag;
+
+  if (!methods) {
+    Object.extend(Form, Form.Methods);
+    Object.extend(Form.Element, Form.Element.Methods);
+    Object.extend(Element.Methods.ByTag, {
+      "FORM":     Object.clone(Form.Methods),
+      "INPUT":    Object.clone(Form.Element.Methods),
+      "SELECT":   Object.clone(Form.Element.Methods),
+      "TEXTAREA": Object.clone(Form.Element.Methods)
+    });
+  }
+
+  if (arguments.length == 2) {
+    var tagName = methods;
+    methods = arguments[1];
+  }
+
+  if (!tagName) Object.extend(Element.Methods, methods || { });
+  else {
+    if (Object.isArray(tagName)) tagName.each(extend);
+    else extend(tagName);
+  }
+
+  function extend(tagName) {
+    tagName = tagName.toUpperCase();
+    if (!Element.Methods.ByTag[tagName])
+      Element.Methods.ByTag[tagName] = { };
+    Object.extend(Element.Methods.ByTag[tagName], methods);
+  }
+
+  function copy(methods, destination, onlyIfAbsent) {
+    onlyIfAbsent = onlyIfAbsent || false;
+    for (var property in methods) {
+      var value = methods[property];
+      if (!Object.isFunction(value)) continue;
+      if (!onlyIfAbsent || !(property in destination))
+        destination[property] = value.methodize();
+    }
+  }
+
+  function findDOMClass(tagName) {
+    var klass;
+    var trans = {
+      "OPTGROUP": "OptGroup", "TEXTAREA": "TextArea", "P": "Paragraph",
+      "FIELDSET": "FieldSet", "UL": "UList", "OL": "OList", "DL": "DList",
+      "DIR": "Directory", "H1": "Heading", "H2": "Heading", "H3": "Heading",
+      "H4": "Heading", "H5": "Heading", "H6": "Heading", "Q": "Quote",
+      "INS": "Mod", "DEL": "Mod", "A": "Anchor", "IMG": "Image", "CAPTION":
+      "TableCaption", "COL": "TableCol", "COLGROUP": "TableCol", "THEAD":
+      "TableSection", "TFOOT": "TableSection", "TBODY": "TableSection", "TR":
+      "TableRow", "TH": "TableCell", "TD": "TableCell", "FRAMESET":
+      "FrameSet", "IFRAME": "IFrame"
+    };
+    if (trans[tagName]) klass = 'HTML' + trans[tagName] + 'Element';
+    if (window[klass]) return window[klass];
+    klass = 'HTML' + tagName + 'Element';
+    if (window[klass]) return window[klass];
+    klass = 'HTML' + tagName.capitalize() + 'Element';
+    if (window[klass]) return window[klass];
+
+    window[klass] = { };
+    window[klass].prototype = document.createElement(tagName).__proto__;
+    return window[klass];
+  }
+
+  if (F.ElementExtensions) {
+    copy(Element.Methods, HTMLElement.prototype);
+    copy(Element.Methods.Simulated, HTMLElement.prototype, true);
+  }
+
+  if (F.SpecificElementExtensions) {
+    for (var tag in Element.Methods.ByTag) {
+      var klass = findDOMClass(tag);
+      if (Object.isUndefined(klass)) continue;
+      copy(T[tag], klass.prototype);
+    }
+  }
+
+  Object.extend(Element, Element.Methods);
+  delete Element.ByTag;
+
+  if (Element.extend.refresh) Element.extend.refresh();
+  Element.cache = { };
+};
+
+document.viewport = {
+  getDimensions: function() {
+    var dimensions = { };
+    $w('width height').each(function(d) {
+      var D = d.capitalize();
+      dimensions[d] = self['inner' + D] ||
+       (document.documentElement['client' + D] || document.body['client' + D]);
+    });
+    return dimensions;
+  },
+
+  getWidth: function() {
+    return this.getDimensions().width;
+  },
+
+  getHeight: function() {
+    return this.getDimensions().height;
+  },
+
+  getScrollOffsets: function() {
+    return Element._returnOffset(
+      window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft,
+      window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop);
+  }
+};
+/* Portions of the Selector class are derived from Jack Slocum’s DomQuery,
+ * part of YUI-Ext version 0.40, distributed under the terms of an MIT-style
+ * license.  Please see http://www.yui-ext.com/ for more information. */
+
+var Selector = Class.create({
+  initialize: function(expression) {
+    this.expression = expression.strip();
+    this.compileMatcher();
+  },
+
+  compileMatcher: function() {
+    // Selectors with namespaced attributes can't use the XPath version
+    if (Prototype.BrowserFeatures.XPath && !(/(\[[\w-]*?:|:checked)/).test(this.expression))
+      return this.compileXPathMatcher();
+
+    var e = this.expression, ps = Selector.patterns, h = Selector.handlers,
+        c = Selector.criteria, le, p, m;
+
+    if (Selector._cache[e]) {
+      this.matcher = Selector._cache[e];
+      return;
+    }
+
+    this.matcher = ["this.matcher = function(root) {",
+                    "var r = root, h = Selector.handlers, c = false, n;"];
+
+    while (e && le != e && (/\S/).test(e)) {
+      le = e;
+      for (var i in ps) {
+        p = ps[i];
+        if (m = e.match(p)) {
+          this.matcher.push(Object.isFunction(c[i]) ? c[i](m) :
+    	      new Template(c[i]).evaluate(m));
+          e = e.replace(m[0], '');
+          break;
+        }
+      }
+    }
+
+    this.matcher.push("return h.unique(n);\n}");
+    eval(this.matcher.join('\n'));
+    Selector._cache[this.expression] = this.matcher;
+  },
+
+  compileXPathMatcher: function() {
+    var e = this.expression, ps = Selector.patterns,
+        x = Selector.xpath, le, m;
+
+    if (Selector._cache[e]) {
+      this.xpath = Selector._cache[e]; return;
+    }
+
+    this.matcher = ['.//*'];
+    while (e && le != e && (/\S/).test(e)) {
+      le = e;
+      for (var i in ps) {
+        if (m = e.match(ps[i])) {
+          this.matcher.push(Object.isFunction(x[i]) ? x[i](m) :
+            new Template(x[i]).evaluate(m));
+          e = e.replace(m[0], '');
+          break;
+        }
+      }
+    }
+
+    this.xpath = this.matcher.join('');
+    Selector._cache[this.expression] = this.xpath;
+  },
+
+  findElements: function(root) {
+    root = root || document;
+    if (this.xpath) return document._getElementsByXPath(this.xpath, root);
+    return this.matcher(root);
+  },
+
+  match: function(element) {
+    this.tokens = [];
+
+    var e = this.expression, ps = Selector.patterns, as = Selector.assertions;
+    var le, p, m;
+
+    while (e && le !== e && (/\S/).test(e)) {
+      le = e;
+      for (var i in ps) {
+        p = ps[i];
+        if (m = e.match(p)) {
+          // use the Selector.assertions methods unless the selector
+          // is too complex.
+          if (as[i]) {
+            this.tokens.push([i, Object.clone(m)]);
+            e = e.replace(m[0], '');
+          } else {
+            // reluctantly do a document-wide search
+            // and look for a match in the array
+            return this.findElements(document).include(element);
+          }
+        }
+      }
+    }
+
+    var match = true, name, matches;
+    for (var i = 0, token; token = this.tokens[i]; i++) {
+      name = token[0], matches = token[1];
+      if (!Selector.assertions[name](element, matches)) {
+        match = false; break;
+      }
+    }
+
+    return match;
+  },
+
+  toString: function() {
+    return this.expression;
+  },
+
+  inspect: function() {
+    return "#<Selector:" + this.expression.inspect() + ">";
+  }
+});
+
+Object.extend(Selector, {
+  _cache: { },
+
+  xpath: {
+    descendant:   "//*",
+    child:        "/*",
+    adjacent:     "/following-sibling::*[1]",
+    laterSibling: '/following-sibling::*',
+    tagName:      function(m) {
+      if (m[1] == '*') return '';
+      return "[local-name()='" + m[1].toLowerCase() +
+             "' or local-name()='" + m[1].toUpperCase() + "']";
+    },
+    className:    "[contains(concat(' ', @class, ' '), ' #{1} ')]",
+    id:           "[@id='#{1}']",
+    attrPresence: "[@#{1}]",
+    attr: function(m) {
+      m[3] = m[5] || m[6];
+      return new Template(Selector.xpath.operators[m[2]]).evaluate(m);
+    },
+    pseudo: function(m) {
+      var h = Selector.xpath.pseudos[m[1]];
+      if (!h) return '';
+      if (Object.isFunction(h)) return h(m);
+      return new Template(Selector.xpath.pseudos[m[1]]).evaluate(m);
+    },
+    operators: {
+      '=':  "[@#{1}='#{3}']",
+      '!=': "[@#{1}!='#{3}']",
+      '^=': "[starts-with(@#{1}, '#{3}')]",
+      '$=': "[substring(@#{1}, (string-length(@#{1}) - string-length('#{3}') + 1))='#{3}']",
+      '*=': "[contains(@#{1}, '#{3}')]",
+      '~=': "[contains(concat(' ', @#{1}, ' '), ' #{3} ')]",
+      '|=': "[contains(concat('-', @#{1}, '-'), '-#{3}-')]"
+    },
+    pseudos: {
+      'first-child': '[not(preceding-sibling::*)]',
+      'last-child':  '[not(following-sibling::*)]',
+      'only-child':  '[not(preceding-sibling::* or following-sibling::*)]',
+      'empty':       "[count(*) = 0 and (count(text()) = 0 or translate(text(), ' \t\r\n', '') = '')]",
+      'checked':     "[@checked]",
+      'disabled':    "[@disabled]",
+      'enabled':     "[not(@disabled)]",
+      'not': function(m) {
+        var e = m[6], p = Selector.patterns,
+            x = Selector.xpath, le, m, v;
+
+        var exclusion = [];
+        while (e && le != e && (/\S/).test(e)) {
+          le = e;
+          for (var i in p) {
+            if (m = e.match(p[i])) {
+              v = Object.isFunction(x[i]) ? x[i](m) : new Template(x[i]).evaluate(m);
+              exclusion.push("(" + v.substring(1, v.length - 1) + ")");
+              e = e.replace(m[0], '');
+              break;
+            }
+          }
+        }
+        return "[not(" + exclusion.join(" and ") + ")]";
+      },
+      'nth-child':      function(m) {
+        return Selector.xpath.pseudos.nth("(count(./preceding-sibling::*) + 1) ", m);
+      },
+      'nth-last-child': function(m) {
+        return Selector.xpath.pseudos.nth("(count(./following-sibling::*) + 1) ", m);
+      },
+      'nth-of-type':    function(m) {
+        return Selector.xpath.pseudos.nth("position() ", m);
+      },
+      'nth-last-of-type': function(m) {
+        return Selector.xpath.pseudos.nth("(last() + 1 - position()) ", m);
+      },
+      'first-of-type':  function(m) {
+        m[6] = "1"; return Selector.xpath.pseudos['nth-of-type'](m);
+      },
+      'last-of-type':   function(m) {
+        m[6] = "1"; return Selector.xpath.pseudos['nth-last-of-type'](m);
+      },
+      'only-of-type':   function(m) {
+        var p = Selector.xpath.pseudos; return p['first-of-type'](m) + p['last-of-type'](m);
+      },
+      nth: function(fragment, m) {
+        var mm, formula = m[6], predicate;
+        if (formula == 'even') formula = '2n+0';
+        if (formula == 'odd')  formula = '2n+1';
+        if (mm = formula.match(/^(\d+)$/)) // digit only
+          return '[' + fragment + "= " + mm[1] + ']';
+        if (mm = formula.match(/^(-?\d*)?n(([+-])(\d+))?/)) { // an+b
+          if (mm[1] == "-") mm[1] = -1;
+          var a = mm[1] ? Number(mm[1]) : 1;
+          var b = mm[2] ? Number(mm[2]) : 0;
+          predicate = "[((#{fragment} - #{b}) mod #{a} = 0) and " +
+          "((#{fragment} - #{b}) div #{a} >= 0)]";
+          return new Template(predicate).evaluate({
+            fragment: fragment, a: a, b: b });
+        }
+      }
+    }
+  },
+
+  criteria: {
+    tagName:      'n = h.tagName(n, r, "#{1}", c);   c = false;',
+    className:    'n = h.className(n, r, "#{1}", c); c = false;',
+    id:           'n = h.id(n, r, "#{1}", c);        c = false;',
+    attrPresence: 'n = h.attrPresence(n, r, "#{1}"); c = false;',
+    attr: function(m) {
+      m[3] = (m[5] || m[6]);
+      return new Template('n = h.attr(n, r, "#{1}", "#{3}", "#{2}"); c = false;').evaluate(m);
+    },
+    pseudo: function(m) {
+      if (m[6]) m[6] = m[6].replace(/"/g, '\\"');
+      return new Template('n = h.pseudo(n, "#{1}", "#{6}", r, c); c = false;').evaluate(m);
+    },
+    descendant:   'c = "descendant";',
+    child:        'c = "child";',
+    adjacent:     'c = "adjacent";',
+    laterSibling: 'c = "laterSibling";'
+  },
+
+  patterns: {
+    // combinators must be listed first
+    // (and descendant needs to be last combinator)
+    laterSibling: /^\s*~\s*/,
+    child:        /^\s*>\s*/,
+    adjacent:     /^\s*\+\s*/,
+    descendant:   /^\s/,
+
+    // selectors follow
+    tagName:      /^\s*(\*|[\w\-]+)(\b|$)?/,
+    id:           /^#([\w\-\*]+)(\b|$)/,
+    className:    /^\.([\w\-\*]+)(\b|$)/,
+    pseudo:       /^:((first|last|nth|nth-last|only)(-child|-of-type)|empty|checked|(en|dis)abled|not)(\((.*?)\))?(\b|$|(?=\s)|(?=:))/,
+    attrPresence: /^\[([\w]+)\]/,
+    attr:         /\[((?:[\w-]*:)?[\w-]+)\s*(?:([!^$*~|]?=)\s*((['"])([^\4]*?)\4|([^'"][^\]]*?)))?\]/
+  },
+
+  // for Selector.match and Element#match
+  assertions: {
+    tagName: function(element, matches) {
+      return matches[1].toUpperCase() == element.tagName.toUpperCase();
+    },
+
+    className: function(element, matches) {
+      return Element.hasClassName(element, matches[1]);
+    },
+
+    id: function(element, matches) {
+      return element.id === matches[1];
+    },
+
+    attrPresence: function(element, matches) {
+      return Element.hasAttribute(element, matches[1]);
+    },
+
+    attr: function(element, matches) {
+      var nodeValue = Element.readAttribute(element, matches[1]);
+      return Selector.operators[matches[2]](nodeValue, matches[3]);
+    }
+  },
+
+  handlers: {
+    // UTILITY FUNCTIONS
+    // joins two collections
+    concat: function(a, b) {
+      for (var i = 0, node; node = b[i]; i++)
+        a.push(node);
+      return a;
+    },
+
+    // marks an array of nodes for counting
+    mark: function(nodes) {
+      for (var i = 0, node; node = nodes[i]; i++)
+        node._counted = true;
+      return nodes;
+    },
+
+    unmark: function(nodes) {
+      for (var i = 0, node; node = nodes[i]; i++)
+        node._counted = undefined;
+      return nodes;
+    },
+
+    // mark each child node with its position (for nth calls)
+    // "ofType" flag indicates whether we're indexing for nth-of-type
+    // rather than nth-child
+    index: function(parentNode, reverse, ofType) {
+      parentNode._counted = true;
+      if (reverse) {
+        for (var nodes = parentNode.childNodes, i = nodes.length - 1, j = 1; i >= 0; i--) {
+          var node = nodes[i];
+          if (node.nodeType == 1 && (!ofType || node._counted)) node.nodeIndex = j++;
+        }
+      } else {
+        for (var i = 0, j = 1, nodes = parentNode.childNodes; node = nodes[i]; i++)
+          if (node.nodeType == 1 && (!ofType || node._counted)) node.nodeIndex = j++;
+      }
+    },
+
+    // filters out duplicates and extends all nodes
+    unique: function(nodes) {
+      if (nodes.length == 0) return nodes;
+      var results = [], n;
+      for (var i = 0, l = nodes.length; i < l; i++)
+        if (!(n = nodes[i])._counted) {
+          n._counted = true;
+          results.push(Element.extend(n));
+        }
+      return Selector.handlers.unmark(results);
+    },
+
+    // COMBINATOR FUNCTIONS
+    descendant: function(nodes) {
+      var h = Selector.handlers;
+      for (var i = 0, results = [], node; node = nodes[i]; i++)
+        h.concat(results, node.getElementsByTagName('*'));
+      return results;
+    },
+
+    child: function(nodes) {
+      var h = Selector.handlers;
+      for (var i = 0, results = [], node; node = nodes[i]; i++) {
+        for (var j = 0, children = [], child; child = node.childNodes[j]; j++)
+          if (child.nodeType == 1 && child.tagName != '!') results.push(child);
+      }
+      return results;
+    },
+
+    adjacent: function(nodes) {
+      for (var i = 0, results = [], node; node = nodes[i]; i++) {
+        var next = this.nextElementSibling(node);
+        if (next) results.push(next);
+      }
+      return results;
+    },
+
+    laterSibling: function(nodes) {
+      var h = Selector.handlers;
+      for (var i = 0, results = [], node; node = nodes[i]; i++)
+        h.concat(results, Element.nextSiblings(node));
+      return results;
+    },
+
+    nextElementSibling: function(node) {
+      while (node = node.nextSibling)
+	      if (node.nodeType == 1) return node;
+      return null;
+    },
+
+    previousElementSibling: function(node) {
+      while (node = node.previousSibling)
+        if (node.nodeType == 1) return node;
+      return null;
+    },
+
+    // TOKEN FUNCTIONS
+    tagName: function(nodes, root, tagName, combinator) {
+      tagName = tagName.toUpperCase();
+      var results = [], h = Selector.handlers;
+      if (nodes) {
+        if (combinator) {
+          // fastlane for ordinary descendant combinators
+          if (combinator == "descendant") {
+            for (var i = 0, node; node = nodes[i]; i++)
+              h.concat(results, node.getElementsByTagName(tagName));
+            return results;
+          } else nodes = this[combinator](nodes);
+          if (tagName == "*") return nodes;
+        }
+        for (var i = 0, node; node = nodes[i]; i++)
+          if (node.tagName.toUpperCase() == tagName) results.push(node);
+        return results;
+      } else return root.getElementsByTagName(tagName);
+    },
+
+    id: function(nodes, root, id, combinator) {
+      var targetNode = $(id), h = Selector.handlers;
+      if (!targetNode) return [];
+      if (!nodes && root == document) return [targetNode];
+      if (nodes) {
+        if (combinator) {
+          if (combinator == 'child') {
+            for (var i = 0, node; node = nodes[i]; i++)
+              if (targetNode.parentNode == node) return [targetNode];
+          } else if (combinator == 'descendant') {
+            for (var i = 0, node; node = nodes[i]; i++)
+              if (Element.descendantOf(targetNode, node)) return [targetNode];
+          } else if (combinator == 'adjacent') {
+            for (var i = 0, node; node = nodes[i]; i++)
+              if (Selector.handlers.previousElementSibling(targetNode) == node)
+                return [targetNode];
+          } else nodes = h[combinator](nodes);
+        }
+        for (var i = 0, node; node = nodes[i]; i++)
+          if (node == targetNode) return [targetNode];
+        return [];
+      }
+      return (targetNode && Element.descendantOf(targetNode, root)) ? [targetNode] : [];
+    },
+
+    className: function(nodes, root, className, combinator) {
+      if (nodes && combinator) nodes = this[combinator](nodes);
+      return Selector.handlers.byClassName(nodes, root, className);
+    },
+
+    byClassName: function(nodes, root, className) {
+      if (!nodes) nodes = Selector.handlers.descendant([root]);
+      var needle = ' ' + className + ' ';
+      for (var i = 0, results = [], node, nodeClassName; node = nodes[i]; i++) {
+        nodeClassName = node.className;
+        if (nodeClassName.length == 0) continue;
+        if (nodeClassName == className || (' ' + nodeClassName + ' ').include(needle))
+          results.push(node);
+      }
+      return results;
+    },
+
+    attrPresence: function(nodes, root, attr) {
+      if (!nodes) nodes = root.getElementsByTagName("*");
+      var results = [];
+      for (var i = 0, node; node = nodes[i]; i++)
+        if (Element.hasAttribute(node, attr)) results.push(node);
+      return results;
+    },
+
+    attr: function(nodes, root, attr, value, operator) {
+      if (!nodes) nodes = root.getElementsByTagName("*");
+      var handler = Selector.operators[operator], results = [];
+      for (var i = 0, node; node = nodes[i]; i++) {
+        var nodeValue = Element.readAttribute(node, attr);
+        if (nodeValue === null) continue;
+        if (handler(nodeValue, value)) results.push(node);
+      }
+      return results;
+    },
+
+    pseudo: function(nodes, name, value, root, combinator) {
+      if (nodes && combinator) nodes = this[combinator](nodes);
+      if (!nodes) nodes = root.getElementsByTagName("*");
+      return Selector.pseudos[name](nodes, value, root);
+    }
+  },
+
+  pseudos: {
+    'first-child': function(nodes, value, root) {
+      for (var i = 0, results = [], node; node = nodes[i]; i++) {
+        if (Selector.handlers.previousElementSibling(node)) continue;
+          results.push(node);
+      }
+      return results;
+    },
+    'last-child': function(nodes, value, root) {
+      for (var i = 0, results = [], node; node = nodes[i]; i++) {
+        if (Selector.handlers.nextElementSibling(node)) continue;
+          results.push(node);
+      }
+      return results;
+    },
+    'only-child': function(nodes, value, root) {
+      var h = Selector.handlers;
+      for (var i = 0, results = [], node; node = nodes[i]; i++)
+        if (!h.previousElementSibling(node) && !h.nextElementSibling(node))
+          results.push(node);
+      return results;
+    },
+    'nth-child':        function(nodes, formula, root) {
+      return Selector.pseudos.nth(nodes, formula, root);
+    },
+    'nth-last-child':   function(nodes, formula, root) {
+      return Selector.pseudos.nth(nodes, formula, root, true);
+    },
+    'nth-of-type':      function(nodes, formula, root) {
+      return Selector.pseudos.nth(nodes, formula, root, false, true);
+    },
+    'nth-last-of-type': function(nodes, formula, root) {
+      return Selector.pseudos.nth(nodes, formula, root, true, true);
+    },
+    'first-of-type':    function(nodes, formula, root) {
+      return Selector.pseudos.nth(nodes, "1", root, false, true);
+    },
+    'last-of-type':     function(nodes, formula, root) {
+      return Selector.pseudos.nth(nodes, "1", root, true, true);
+    },
+    'only-of-type':     function(nodes, formula, root) {
+      var p = Selector.pseudos;
+      return p['last-of-type'](p['first-of-type'](nodes, formula, root), formula, root);
+    },
+
+    // handles the an+b logic
+    getIndices: function(a, b, total) {
+      if (a == 0) return b > 0 ? [b] : [];
+      return $R(1, total).inject([], function(memo, i) {
+        if (0 == (i - b) % a && (i - b) / a >= 0) memo.push(i);
+        return memo;
+      });
+    },
+
+    // handles nth(-last)-child, nth(-last)-of-type, and (first|last)-of-type
+    nth: function(nodes, formula, root, reverse, ofType) {
+      if (nodes.length == 0) return [];
+      if (formula == 'even') formula = '2n+0';
+      if (formula == 'odd')  formula = '2n+1';
+      var h = Selector.handlers, results = [], indexed = [], m;
+      h.mark(nodes);
+      for (var i = 0, node; node = nodes[i]; i++) {
+        if (!node.parentNode._counted) {
+          h.index(node.parentNode, reverse, ofType);
+          indexed.push(node.parentNode);
+        }
+      }
+      if (formula.match(/^\d+$/)) { // just a number
+        formula = Number(formula);
+        for (var i = 0, node; node = nodes[i]; i++)
+          if (node.nodeIndex == formula) results.push(node);
+      } else if (m = formula.match(/^(-?\d*)?n(([+-])(\d+))?/)) { // an+b
+        if (m[1] == "-") m[1] = -1;
+        var a = m[1] ? Number(m[1]) : 1;
+        var b = m[2] ? Number(m[2]) : 0;
+        var indices = Selector.pseudos.getIndices(a, b, nodes.length);
+        for (var i = 0, node, l = indices.length; node = nodes[i]; i++) {
+          for (var j = 0; j < l; j++)
+            if (node.nodeIndex == indices[j]) results.push(node);
+        }
+      }
+      h.unmark(nodes);
+      h.unmark(indexed);
+      return results;
+    },
+
+    'empty': function(nodes, value, root) {
+      for (var i = 0, results = [], node; node = nodes[i]; i++) {
+        // IE treats comments as element nodes
+        if (node.tagName == '!' || (node.firstChild && !node.innerHTML.match(/^\s*$/))) continue;
+        results.push(node);
+      }
+      return results;
+    },
+
+    'not': function(nodes, selector, root) {
+      var h = Selector.handlers, selectorType, m;
+      var exclusions = new Selector(selector).findElements(root);
+      h.mark(exclusions);
+      for (var i = 0, results = [], node; node = nodes[i]; i++)
+        if (!node._counted) results.push(node);
+      h.unmark(exclusions);
+      return results;
+    },
+
+    'enabled': function(nodes, value, root) {
+      for (var i = 0, results = [], node; node = nodes[i]; i++)
+        if (!node.disabled) results.push(node);
+      return results;
+    },
+
+    'disabled': function(nodes, value, root) {
+      for (var i = 0, results = [], node; node = nodes[i]; i++)
+        if (node.disabled) results.push(node);
+      return results;
+    },
+
+    'checked': function(nodes, value, root) {
+      for (var i = 0, results = [], node; node = nodes[i]; i++)
+        if (node.checked) results.push(node);
+      return results;
+    }
+  },
+
+  operators: {
+    '=':  function(nv, v) { return nv == v; },
+    '!=': function(nv, v) { return nv != v; },
+    '^=': function(nv, v) { return nv.startsWith(v); },
+    '$=': function(nv, v) { return nv.endsWith(v); },
+    '*=': function(nv, v) { return nv.include(v); },
+    '~=': function(nv, v) { return (' ' + nv + ' ').include(' ' + v + ' '); },
+    '|=': function(nv, v) { return ('-' + nv.toUpperCase() + '-').include('-' + v.toUpperCase() + '-'); }
+  },
+
+  matchElements: function(elements, expression) {
+    var matches = new Selector(expression).findElements(), h = Selector.handlers;
+    h.mark(matches);
+    for (var i = 0, results = [], element; element = elements[i]; i++)
+      if (element._counted) results.push(element);
+    h.unmark(matches);
+    return results;
+  },
+
+  findElement: function(elements, expression, index) {
+    if (Object.isNumber(expression)) {
+      index = expression; expression = false;
+    }
+    return Selector.matchElements(elements, expression || '*')[index || 0];
+  },
+
+  findChildElements: function(element, expressions) {
+    var exprs = expressions.join(','), expressions = [];
+    exprs.scan(/(([\w#:.~>+()\s-]+|\*|\[.*?\])+)\s*(,|$)/, function(m) {
+      expressions.push(m[1].strip());
+    });
+    var results = [], h = Selector.handlers;
+    for (var i = 0, l = expressions.length, selector; i < l; i++) {
+      selector = new Selector(expressions[i].strip());
+      h.concat(results, selector.findElements(element));
+    }
+    return (l > 1) ? h.unique(results) : results;
+  }
+});
+
+function $$() {
+  return Selector.findChildElements(document, $A(arguments));
+}
+var Form = {
+  reset: function(form) {
+    $(form).reset();
+    return form;
+  },
+
+  serializeElements: function(elements, options) {
+    if (typeof options != 'object') options = { hash: !!options };
+    else if (options.hash === undefined) options.hash = true;
+    var key, value, submitted = false, submit = options.submit;
+
+    var data = elements.inject({ }, function(result, element) {
+      if (!element.disabled && element.name) {
+        key = element.name; value = $(element).getValue();
+        if (value != null && (element.type != 'submit' || (!submitted &&
+            submit !== false && (!submit || key == submit) && (submitted = true)))) {
+          if (key in result) {
+            // a key is already present; construct an array of values
+            if (!Object.isArray(result[key])) result[key] = [result[key]];
+            result[key].push(value);
+          }
+          else result[key] = value;
+        }
+      }
+      return result;
+    });
+
+    return options.hash ? data : Object.toQueryString(data);
+  }
+};
+
+Form.Methods = {
+  serialize: function(form, options) {
+    return Form.serializeElements(Form.getElements(form), options);
+  },
+
+  getElements: function(form) {
+    return $A($(form).getElementsByTagName('*')).inject([],
+      function(elements, child) {
+        if (Form.Element.Serializers[child.tagName.toLowerCase()])
+          elements.push(Element.extend(child));
+        return elements;
+      }
+    );
+  },
+
+  getInputs: function(form, typeName, name) {
+    form = $(form);
+    var inputs = form.getElementsByTagName('input');
+
+    if (!typeName && !name) return $A(inputs).map(Element.extend);
+
+    for (var i = 0, matchingInputs = [], length = inputs.length; i < length; i++) {
+      var input = inputs[i];
+      if ((typeName && input.type != typeName) || (name && input.name != name))
+        continue;
+      matchingInputs.push(Element.extend(input));
+    }
+
+    return matchingInputs;
+  },
+
+  disable: function(form) {
+    form = $(form);
+    Form.getElements(form).invoke('disable');
+    return form;
+  },
+
+  enable: function(form) {
+    form = $(form);
+    Form.getElements(form).invoke('enable');
+    return form;
+  },
+
+  findFirstElement: function(form) {
+    var elements = $(form).getElements().findAll(function(element) {
+      return 'hidden' != element.type && !element.disabled;
+    });
+    var firstByIndex = elements.findAll(function(element) {
+      return element.hasAttribute('tabIndex') && element.tabIndex >= 0;
+    }).sortBy(function(element) { return element.tabIndex }).first();
+
+    return firstByIndex ? firstByIndex : elements.find(function(element) {
+      return ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
+    });
+  },
+
+  focusFirstElement: function(form) {
+    form = $(form);
+    form.findFirstElement().activate();
+    return form;
+  },
+
+  request: function(form, options) {
+    form = $(form), options = Object.clone(options || { });
+
+    var params = options.parameters, action = form.readAttribute('action') || '';
+    if (action.blank()) action = window.location.href;
+    options.parameters = form.serialize(true);
+
+    if (params) {
+      if (Object.isString(params)) params = params.toQueryParams();
+      Object.extend(options.parameters, params);
+    }
+
+    if (form.hasAttribute('method') && !options.method)
+      options.method = form.method;
+
+    return new Ajax.Request(action, options);
+  }
+};
+
+/*--------------------------------------------------------------------------*/
+
+Form.Element = {
+  focus: function(element) {
+    $(element).focus();
+    return element;
+  },
+
+  select: function(element) {
+    $(element).select();
+    return element;
+  }
+};
+
+Form.Element.Methods = {
+  serialize: function(element) {
+    element = $(element);
+    if (!element.disabled && element.name) {
+      var value = element.getValue();
+      if (value != undefined) {
+        var pair = { };
+        pair[element.name] = value;
+        return Object.toQueryString(pair);
+      }
+    }
+    return '';
+  },
+
+  getValue: function(element) {
+    element = $(element);
+    var method = element.tagName.toLowerCase();
+    return Form.Element.Serializers[method](element);
+  },
+
+  setValue: function(element, value) {
+    element = $(element);
+    var method = element.tagName.toLowerCase();
+    Form.Element.Serializers[method](element, value);
+    return element;
+  },
+
+  clear: function(element) {
+    $(element).value = '';
+    return element;
+  },
+
+  present: function(element) {
+    return $(element).value != '';
+  },
+
+  activate: function(element) {
+    element = $(element);
+    try {
+      element.focus();
+      if (element.select && (element.tagName.toLowerCase() != 'input' ||
+          !['button', 'reset', 'submit'].include(element.type)))
+        element.select();
+    } catch (e) { }
+    return element;
+  },
+
+  disable: function(element) {
+    element = $(element);
+    element.blur();
+    element.disabled = true;
+    return element;
+  },
+
+  enable: function(element) {
+    element = $(element);
+    element.disabled = false;
+    return element;
+  }
+};
+
+/*--------------------------------------------------------------------------*/
+
+var Field = Form.Element;
+var $F = Form.Element.Methods.getValue;
+
+/*--------------------------------------------------------------------------*/
+
+Form.Element.Serializers = {
+  input: function(element, value) {
+    switch (element.type.toLowerCase()) {
+      case 'checkbox':
+      case 'radio':
+        return Form.Element.Serializers.inputSelector(element, value);
+      default:
+        return Form.Element.Serializers.textarea(element, value);
+    }
+  },
+
+  inputSelector: function(element, value) {
+    if (value === undefined) return element.checked ? element.value : null;
+    else element.checked = !!value;
+  },
+
+  textarea: function(element, value) {
+    if (value === undefined) return element.value;
+    else element.value = value;
+  },
+
+  select: function(element, index) {
+    if (index === undefined)
+      return this[element.type == 'select-one' ?
+        'selectOne' : 'selectMany'](element);
+    else {
+      var opt, value, single = !Object.isArray(index);
+      for (var i = 0, length = element.length; i < length; i++) {
+        opt = element.options[i];
+        value = this.optionValue(opt);
+        if (single) {
+          if (value == index) {
+            opt.selected = true;
+            return;
+          }
+        }
+        else opt.selected = index.include(value);
+      }
+    }
+  },
+
+  selectOne: function(element) {
+    var index = element.selectedIndex;
+    return index >= 0 ? this.optionValue(element.options[index]) : null;
+  },
+
+  selectMany: function(element) {
+    var values, length = element.length;
+    if (!length) return null;
+
+    for (var i = 0, values = []; i < length; i++) {
+      var opt = element.options[i];
+      if (opt.selected) values.push(this.optionValue(opt));
+    }
+    return values;
+  },
+
+  optionValue: function(opt) {
+    // extend element because hasAttribute may not be native
+    return Element.extend(opt).hasAttribute('value') ? opt.value : opt.text;
+  }
+};
+
+/*--------------------------------------------------------------------------*/
+
+Abstract.TimedObserver = Class.create(PeriodicalExecuter, {
+  initialize: function($super, element, frequency, callback) {
+    $super(callback, frequency);
+    this.element   = $(element);
+    this.lastValue = this.getValue();
+  },
+
+  execute: function() {
+    var value = this.getValue();
+    if (Object.isString(this.lastValue) && Object.isString(value) ?
+        this.lastValue != value : String(this.lastValue) != String(value)) {
+      this.callback(this.element, value);
+      this.lastValue = value;
+    }
+  }
+});
+
+Form.Element.Observer = Class.create(Abstract.TimedObserver, {
+  getValue: function() {
+    return Form.Element.getValue(this.element);
+  }
+});
+
+Form.Observer = Class.create(Abstract.TimedObserver, {
+  getValue: function() {
+    return Form.serialize(this.element);
+  }
+});
+
+/*--------------------------------------------------------------------------*/
+
+Abstract.EventObserver = Class.create({
+  initialize: function(element, callback) {
+    this.element  = $(element);
+    this.callback = callback;
+
+    this.lastValue = this.getValue();
+    if (this.element.tagName.toLowerCase() == 'form')
+      this.registerFormCallbacks();
+    else
+      this.registerCallback(this.element);
+  },
+
+  onElementEvent: function() {
+    var value = this.getValue();
+    if (this.lastValue != value) {
+      this.callback(this.element, value);
+      this.lastValue = value;
+    }
+  },
+
+  registerFormCallbacks: function() {
+    Form.getElements(this.element).each(this.registerCallback, this);
+  },
+
+  registerCallback: function(element) {
+    if (element.type) {
+      switch (element.type.toLowerCase()) {
+        case 'checkbox':
+        case 'radio':
+          Event.observe(element, 'click', this.onElementEvent.bind(this));
+          break;
+        default:
+          Event.observe(element, 'change', this.onElementEvent.bind(this));
+          break;
+      }
+    }
+  }
+});
+
+Form.Element.EventObserver = Class.create(Abstract.EventObserver, {
+  getValue: function() {
+    return Form.Element.getValue(this.element);
+  }
+});
+
+Form.EventObserver = Class.create(Abstract.EventObserver, {
+  getValue: function() {
+    return Form.serialize(this.element);
+  }
+});
+if (!window.Event) var Event = { };
+
+Object.extend(Event, {
+  KEY_BACKSPACE: 8,
+  KEY_TAB:       9,
+  KEY_RETURN:   13,
+  KEY_ESC:      27,
+  KEY_LEFT:     37,
+  KEY_UP:       38,
+  KEY_RIGHT:    39,
+  KEY_DOWN:     40,
+  KEY_DELETE:   46,
+  KEY_HOME:     36,
+  KEY_END:      35,
+  KEY_PAGEUP:   33,
+  KEY_PAGEDOWN: 34,
+  KEY_INSERT:   45,
+
+  cache: { },
+
+  relatedTarget: function(event) {
+    var element;
+    switch(event.type) {
+      case 'mouseover': element = event.fromElement; break;
+      case 'mouseout':  element = event.toElement;   break;
+      default: return null;
+    }
+    return Element.extend(element);
+  }
+});
+
+Event.Methods = (function() {
+  var isButton;
+
+  if (Prototype.Browser.IE) {
+    var buttonMap = { 0: 1, 1: 4, 2: 2 };
+    isButton = function(event, code) {
+      return event.button == buttonMap[code];
+    };
+
+  } else if (Prototype.Browser.WebKit) {
+    isButton = function(event, code) {
+      switch (code) {
+        case 0: return event.which == 1 && !event.metaKey;
+        case 1: return event.which == 1 && event.metaKey;
+        default: return false;
+      }
+    };
+
+  } else {
+    isButton = function(event, code) {
+      return event.which ? (event.which === code + 1) : (event.button === code);
+    };
+  }
+
+  return {
+    isLeftClick:   function(event) { return isButton(event, 0) },
+    isMiddleClick: function(event) { return isButton(event, 1) },
+    isRightClick:  function(event) { return isButton(event, 2) },
+
+    element: function(event) {
+      var node = Event.extend(event).target;
+      return Element.extend(node.nodeType == Node.TEXT_NODE ? node.parentNode : node);
+    },
+
+    findElement: function(event, expression) {
+      var element = Event.element(event);
+      return element.match(expression) ? element : element.up(expression);
+    },
+
+    pointer: function(event) {
+      return {
+        x: event.pageX || (event.clientX +
+          (document.documentElement.scrollLeft || document.body.scrollLeft)),
+        y: event.pageY || (event.clientY +
+          (document.documentElement.scrollTop || document.body.scrollTop))
+      };
+    },
+
+    pointerX: function(event) { return Event.pointer(event).x },
+    pointerY: function(event) { return Event.pointer(event).y },
+
+    stop: function(event) {
+      Event.extend(event);
+      event.preventDefault();
+      event.stopPropagation();
+      event.stopped = true;
+    }
+  };
+})();
+
+Event.extend = (function() {
+  var methods = Object.keys(Event.Methods).inject({ }, function(m, name) {
+    m[name] = Event.Methods[name].methodize();
+    return m;
+  });
+
+  if (Prototype.Browser.IE) {
+    Object.extend(methods, {
+      stopPropagation: function() { this.cancelBubble = true },
+      preventDefault:  function() { this.returnValue = false },
+      inspect: function() { return "[object Event]" }
+    });
+
+    return function(event) {
+      if (!event) return false;
+      if (event._extendedByPrototype) return event;
+
+      event._extendedByPrototype = Prototype.emptyFunction;
+      var pointer = Event.pointer(event);
+      Object.extend(event, {
+        target: event.srcElement,
+        relatedTarget: Event.relatedTarget(event),
+        pageX:  pointer.x,
+        pageY:  pointer.y
+      });
+      return Object.extend(event, methods);
+    };
+
+  } else {
+    Event.prototype = Event.prototype || document.createEvent("HTMLEvents").__proto__;
+    Object.extend(Event.prototype, methods);
+    return Prototype.K;
+  }
+})();
+
+Object.extend(Event, (function() {
+  var cache = Event.cache;
+
+  function getEventID(element) {
+    if (element._eventID) return element._eventID;
+    arguments.callee.id = arguments.callee.id || 1;
+    return element._eventID = ++arguments.callee.id;
+  }
+
+  function getDOMEventName(eventName) {
+    if (eventName && eventName.include(':')) return "dataavailable";
+    return eventName;
+  }
+
+  function getCacheForID(id) {
+    return cache[id] = cache[id] || { };
+  }
+
+  function getWrappersForEventName(id, eventName) {
+    var c = getCacheForID(id);
+    return c[eventName] = c[eventName] || [];
+  }
+
+  function createWrapper(element, eventName, handler) {
+    var id = getEventID(element);
+    var c = getWrappersForEventName(id, eventName);
+    if (c.pluck("handler").include(handler)) return false;
+
+    var wrapper = function(event) {
+      if (!Event || !Event.extend ||
+        (event.eventName && event.eventName != eventName))
+          return false;
+
+      Event.extend(event);
+      handler.call(element, event)
+    };
+
+    wrapper.handler = handler;
+    c.push(wrapper);
+    return wrapper;
+  }
+
+  function findWrapper(id, eventName, handler) {
+    var c = getWrappersForEventName(id, eventName);
+    return c.find(function(wrapper) { return wrapper.handler == handler });
+  }
+
+  function destroyWrapper(id, eventName, handler) {
+    var c = getCacheForID(id);
+    if (!c[eventName]) return false;
+    c[eventName] = c[eventName].without(findWrapper(id, eventName, handler));
+  }
+
+  function destroyCache() {
+    for (var id in cache)
+      for (var eventName in cache[id])
+        cache[id][eventName] = null;
+  }
+
+  if (window.attachEvent) {
+    window.attachEvent("onunload", destroyCache);
+  }
+
+  return {
+    observe: function(element, eventName, handler) {
+      element = $(element);
+      var name = getDOMEventName(eventName);
+
+      var wrapper = createWrapper(element, eventName, handler);
+      if (!wrapper) return element;
+
+      if (element.addEventListener) {
+        element.addEventListener(name, wrapper, false);
+      } else {
+        element.attachEvent("on" + name, wrapper);
+      }
+
+      return element;
+    },
+
+    stopObserving: function(element, eventName, handler) {
+      element = $(element);
+      var id = getEventID(element), name = getDOMEventName(eventName);
+
+      if (!handler && eventName) {
+        getWrappersForEventName(id, eventName).each(function(wrapper) {
+          element.stopObserving(eventName, wrapper.handler);
+        });
+        return element;
+
+      } else if (!eventName) {
+        Object.keys(getCacheForID(id)).each(function(eventName) {
+          element.stopObserving(eventName);
+        });
+        return element;
+      }
+
+      var wrapper = findWrapper(id, eventName, handler);
+      if (!wrapper) return element;
+
+      if (element.removeEventListener) {
+        element.removeEventListener(name, wrapper, false);
+      } else {
+        element.detachEvent("on" + name, wrapper);
+      }
+
+      destroyWrapper(id, eventName, handler);
+
+      return element;
+    },
+
+    fire: function(element, eventName, memo) {
+      element = $(element);
+      if (element == document && document.createEvent && !element.dispatchEvent)
+        element = document.documentElement;
+
+      if (document.createEvent) {
+        var event = document.createEvent("HTMLEvents");
+        event.initEvent("dataavailable", true, true);
+      } else {
+        var event = document.createEventObject();
+        event.eventType = "ondataavailable";
+      }
+
+      event.eventName = eventName;
+      event.memo = memo || { };
+
+      if (document.createEvent) {
+        element.dispatchEvent(event);
+      } else {
+        element.fireEvent(event.eventType, event);
+      }
+
+      return event;
+    }
+  };
+})());
+
+Object.extend(Event, Event.Methods);
+
+Element.addMethods({
+  fire:          Event.fire,
+  observe:       Event.observe,
+  stopObserving: Event.stopObserving
+});
+
+Object.extend(document, {
+  fire:          Element.Methods.fire.methodize(),
+  observe:       Element.Methods.observe.methodize(),
+  stopObserving: Element.Methods.stopObserving.methodize()
+});
+
+(function() {
+  /* Support for the DOMContentLoaded event is based on work by Dan Webb,
+     Matthias Miller, Dean Edwards and John Resig. */
+
+  var timer, fired = false;
+
+  function fireContentLoadedEvent() {
+    if (fired) return;
+    if (timer) window.clearInterval(timer);
+    document.fire("dom:loaded");
+    fired = true;
+  }
+
+  if (document.addEventListener) {
+    if (Prototype.Browser.WebKit) {
+      timer = window.setInterval(function() {
+        if (/loaded|complete/.test(document.readyState))
+          fireContentLoadedEvent();
+      }, 0);
+
+      Event.observe(window, "load", fireContentLoadedEvent);
+
+    } else {
+      document.addEventListener("DOMContentLoaded",
+        fireContentLoadedEvent, false);
+    }
+
+  } else {
+    document.write("<script id=__onDOMContentLoaded defer src=//:><\/script>");
+    $("__onDOMContentLoaded").onreadystatechange = function() {
+      if (this.readyState == "complete") {
+        this.onreadystatechange = null;
+        fireContentLoadedEvent();
+      }
+    };
+  }
+})();
+/*------------------------------- DEPRECATED -------------------------------*/
+
+Hash.toQueryString = Object.toQueryString;
+
+var Toggle = { display: Element.toggle };
+
+Element.Methods.childOf = Element.Methods.descendantOf;
+
+var Insertion = {
+  Before: function(element, content) {
+    return Element.insert(element, {before:content});
+  },
+
+  Top: function(element, content) {
+    return Element.insert(element, {top:content});
+  },
+
+  Bottom: function(element, content) {
+    return Element.insert(element, {bottom:content});
+  },
+
+  After: function(element, content) {
+    return Element.insert(element, {after:content});
+  }
+};
+
+var $continue = new Error('"throw $continue" is deprecated, use "return" instead');
+
+// This should be moved to script.aculo.us; notice the deprecated methods
+// further below, that map to the newer Element methods.
+var Position = {
+  // set to true if needed, warning: firefox performance problems
+  // NOT neeeded for page scrolling, only if draggable contained in
+  // scrollable elements
+  includeScrollOffsets: false,
+
+  // must be called before calling withinIncludingScrolloffset, every time the
+  // page is scrolled
+  prepare: function() {
+    this.deltaX =  window.pageXOffset
+                || document.documentElement.scrollLeft
+                || document.body.scrollLeft
+                || 0;
+    this.deltaY =  window.pageYOffset
+                || document.documentElement.scrollTop
+                || document.body.scrollTop
+                || 0;
+  },
+
+  // caches x/y coordinate pair to use with overlap
+  within: function(element, x, y) {
+    if (this.includeScrollOffsets)
+      return this.withinIncludingScrolloffsets(element, x, y);
+    this.xcomp = x;
+    this.ycomp = y;
+    this.offset = Element.cumulativeOffset(element);
+
+    return (y >= this.offset[1] &&
+            y <  this.offset[1] + element.offsetHeight &&
+            x >= this.offset[0] &&
+            x <  this.offset[0] + element.offsetWidth);
+  },
+
+  withinIncludingScrolloffsets: function(element, x, y) {
+    var offsetcache = Element.cumulativeScrollOffset(element);
+
+    this.xcomp = x + offsetcache[0] - this.deltaX;
+    this.ycomp = y + offsetcache[1] - this.deltaY;
+    this.offset = Element.cumulativeOffset(element);
+
+    return (this.ycomp >= this.offset[1] &&
+            this.ycomp <  this.offset[1] + element.offsetHeight &&
+            this.xcomp >= this.offset[0] &&
+            this.xcomp <  this.offset[0] + element.offsetWidth);
+  },
+
+  // within must be called directly before
+  overlap: function(mode, element) {
+    if (!mode) return 0;
+    if (mode == 'vertical')
+      return ((this.offset[1] + element.offsetHeight) - this.ycomp) /
+        element.offsetHeight;
+    if (mode == 'horizontal')
+      return ((this.offset[0] + element.offsetWidth) - this.xcomp) /
+        element.offsetWidth;
+  },
+
+  // Deprecation layer -- use newer Element methods now (1.5.2).
+
+  cumulativeOffset: Element.Methods.cumulativeOffset,
+
+  positionedOffset: Element.Methods.positionedOffset,
+
+  absolutize: function(element) {
+    Position.prepare();
+    return Element.absolutize(element);
+  },
+
+  relativize: function(element) {
+    Position.prepare();
+    return Element.relativize(element);
+  },
+
+  realOffset: Element.Methods.cumulativeScrollOffset,
+
+  offsetParent: Element.Methods.getOffsetParent,
+
+  page: Element.Methods.viewportOffset,
+
+  clone: function(source, target, options) {
+    options = options || { };
+    return Element.clonePosition(target, source, options);
+  }
+};
+
+/*--------------------------------------------------------------------------*/
+
+if (!document.getElementsByClassName) document.getElementsByClassName = function(instanceMethods){
+  function iter(name) {
+    return name.blank() ? null : "[contains(concat(' ', @class, ' '), ' " + name + " ')]";
+  }
+
+  instanceMethods.getElementsByClassName = Prototype.BrowserFeatures.XPath ?
+  function(element, className) {
+    className = className.toString().strip();
+    var cond = /\s/.test(className) ? $w(className).map(iter).join('') : iter(className);
+    return cond ? document._getElementsByXPath('.//*' + cond, element) : [];
+  } : function(element, className) {
+    className = className.toString().strip();
+    var elements = [], classNames = (/\s/.test(className) ? $w(className) : null);
+    if (!classNames && !className) return elements;
+
+    var nodes = $(element).getElementsByTagName('*');
+    className = ' ' + className + ' ';
+
+    for (var i = 0, child, cn; child = nodes[i]; i++) {
+      if (child.className && (cn = ' ' + child.className + ' ') && (cn.include(className) ||
+          (classNames && classNames.all(function(name) {
+            return !name.toString().blank() && cn.include(' ' + name + ' ');
+          }))))
+        elements.push(Element.extend(child));
+    }
+    return elements;
+  };
+
+  return function(className, parentElement) {
+    return $(parentElement || document.body).getElementsByClassName(className);
+  };
+}(Element.Methods);
+
+/*--------------------------------------------------------------------------*/
+
+Element.ClassNames = Class.create();
+Element.ClassNames.prototype = {
+  initialize: function(element) {
+    this.element = $(element);
+  },
+
+  _each: function(iterator) {
+    this.element.className.split(/\s+/).select(function(name) {
+      return name.length > 0;
+    })._each(iterator);
+  },
+
+  set: function(className) {
+    this.element.className = className;
+  },
+
+  add: function(classNameToAdd) {
+    if (this.include(classNameToAdd)) return;
+    this.set($A(this).concat(classNameToAdd).join(' '));
+  },
+
+  remove: function(classNameToRemove) {
+    if (!this.include(classNameToRemove)) return;
+    this.set($A(this).without(classNameToRemove).join(' '));
+  },
+
+  toString: function() {
+    return $A(this).join(' ');
+  }
+};
+
+Object.extend(Element.ClassNames.prototype, Enumerable);
+
+/*--------------------------------------------------------------------------*/
+
+Element.addMethods();