/*
	Finds elements on page that match a given CSS selector rule. Some
	complicated rules are not compatible.
	Based on Simon Willison's excellent "getElementsBySelector" function.
	Original code (with comments and description):
		http://simon.incutio.com/archive/2003/03/25/getElementsBySelector
*/
function getElementsBySelector(selector)
{
	var tokens = selector.split(' ');
	var currentContext = new Array(document);
	for(var i=0;i<tokens.length;i++)
	{
		token = tokens[i].replace(/^\s+/,'').replace(/\s+$/,'');
		if(token.indexOf('#') > -1)
		{
			var bits = token.split('#');
			var tagName = bits[0];
			var id = bits[1];
			var element = document.getElementById(id);
			if(tagName && element.nodeName.toLowerCase() != tagName)
				return new Array();
			currentContext = new Array(element);
			continue;
		}

		if(token.indexOf('.') > -1)
		{
			var bits = token.split('.');
			var tagName = bits[0];
			var className = bits[1];
			if(!tagName)
				tagName = '*';

			var found = new Array;
			var foundCount = 0;
			for(var h=0;h<currentContext.length;h++)
			{
				var elements;
				if(tagName == '*')
					elements = currentContext[h].all ? currentContext[h].all : currentContext[h].getElementsByTagName('*');
				else
					elements = currentContext[h].getElementsByTagName(tagName);

				for(var j=0;j<elements.length;j++)
					found[foundCount++] = elements[j];
			}

			currentContext = new Array;
			var currentContextIndex = 0;
			for(var k=0;k<found.length;k++)
			{
				if(found[k].className && found[k].className.match(new RegExp('\\b'+className+'\\b')))
					currentContext[currentContextIndex++] = found[k];
			}

			continue;
	    }

		if(token.match(/^(\w*)\[(\w+)([=~\|\^\$\*]?)=?"?([^\]"]*)"?\]$/))
		{
			var tagName = RegExp.$1;
			var attrName = RegExp.$2;
			var attrOperator = RegExp.$3;
			var attrValue = RegExp.$4;
			if(!tagName)
				tagName = '*';

			var found = new Array;
			var foundCount = 0;
			for(var h=0;h<currentContext.length;h++)
			{
				var elements;
	        	if(tagName == '*')
					elements = currentContext[h].all ? currentContext[h].all : currentContext[h].getElementsByTagName('*');
				else
					elements = currentContext[h].getElementsByTagName(tagName);

				for(var j=0;j<elements.length;j++)
					found[foundCount++] = elements[j];
			}

			currentContext = new Array;
			var currentContextIndex = 0;
			var checkFunction;
			switch(attrOperator)
			{
				case '=':
					checkFunction = function(e) { return (e.getAttribute(attrName) == attrValue); };
					break;
				case '~':
					checkFunction = function(e) { return (e.getAttribute(attrName).match(new RegExp('\\b'+attrValue+'\\b'))); };
					break;
				case '|':
					checkFunction = function(e) { return (e.getAttribute(attrName).match(new RegExp('^'+attrValue+'-?'))); };
					break;
				case '^':
					checkFunction = function(e) { return (e.getAttribute(attrName).indexOf(attrValue) == 0); };
					break;
				case '$':
					checkFunction = function(e) { return (e.getAttribute(attrName).lastIndexOf(attrValue) == e.getAttribute(attrName).length - attrValue.length); };
					break;
				case '*':
					checkFunction = function(e) { return (e.getAttribute(attrName).indexOf(attrValue) > -1); };
					break;
				default :
					checkFunction = function(e) { return e.getAttribute(attrName); };
			}

			currentContext = new Array;
			var currentContextIndex = 0;
			for(var k=0;k<found.length;k++)
			{
				if(checkFunction(found[k]))
					currentContext[currentContextIndex++] = found[k];
			}

			continue;
		}

		tagName = token;
		var found = new Array;
		var foundCount = 0;
		for(var h=0;h<currentContext.length;h++)
		{
			var elements = currentContext[h].getElementsByTagName(tagName);
			for(var j=0;j<elements.length; j++)
				found[foundCount++] = elements[j];
		}

		currentContext = found;
	}

	return currentContext;
}

function extractText(element)
{
	if(typeof element == "string")
		return element;
	else if(typeof element == "undefined")
		return element;
	else if(element.firstChild.innerText)
		return element.firstChild.innerText;
	else if(element.innerText)
		return element.innerText;

	var text = "";
	var kids = element.childNodes;
	for(var i=0;i<kids.length;i++)
	{
		if(kids[i].nodeType == 1)
		text += extractText(kids[i]);
		else if(kids[i].nodeType == 3)
		text += kids[i].nodeValue;
	}

	return text;
}

function addLoadHandler(handler)
{
	if(window.addEventListener)
	{
		window.addEventListener("load",handler,false);
	}
	else if(window.attachEvent)
	{
		window.attachEvent("onload",handler);
	}
	else if(window.onload)
	{
		var oldHandler = window.onload;
		window.onload = function piggyback()
		{
			oldHandler();
			handler();
		};
	}
	else
	{
		window.onload = handler;
	}
}

function showDiv(whichDiv)
{ 
	if (document.getElementById)
		{ 
		var menus;
		var numMenus;
		
		menus = getElementsBySelector('div#header li');
		
		for (i = 0 ; i 	< menus.length ; i++)
			menus[i].id = "";
		
		for (i = 0 ; i < menus.length ; i++)
			{
			var menu = menus[i];
			var menuText = extractText(menu);
			var thisDiv = document.getElementById(menuText);
			
			if (thisDiv.id == extractText(whichDiv))
				{
				menus[i].id = "current";
				thisDiv.style.display = 'block';
				}
			else
				{
				thisDiv.style.display = 'none';
				}
			}
		}
}

function initializeSections()
{
	if (document.getElementById)
		{
		var menus;
		
		menus = getElementsBySelector('div#header li');
		
		if (menus.length > 0)
			showDiv(menus[0]);
		}
}

addLoadHandler(function(){ initializeSections(); });