function setActiveStyleSheet(title) { 
	if (title != null) {
		var i, a, main;
		for(i=0; (a = document.getElementsByTagName("link")[i]); i++) { 
			if(a.getAttribute("rel").indexOf("style")!= -1 && a.getAttribute("title")) 
			{ 
				a.disabled = true; 
				if(a.getAttribute("title") == title)
				{
					a.disabled = false;
				}
			} 
		}
		rewriteToplevelnavImages(title);
	}
} 

function getActiveStyleSheet() { 
var i, a; 
for(i=0; (a = document.getElementsByTagName("link")[i]); i++) { 
if(a.getAttribute("rel").indexOf("style")!= -1 && a.getAttribute("title") &&!a.disabled) return a.getAttribute("title"); 
} 
return null; 
} 


function createCookie(name,value,days) { 
if (days) { 
var date = new Date(); 
date.setTime(date.getTime()+(days*24*60*60*1000)); 
var expires = "; expires="+date.toGMTString(); 
} 
else expires = ""; 
document.cookie = name+"="+value+expires+"; path=/"; 
} 

function readCookie(name) { 
var nameEQ = name + "="; 
var ca = document.cookie.split(';'); 
for(var i=0;i < ca.length;i++) { 
var c = ca[i]; 
while (c.charAt(0)==' ') c = c.substring(1,c.length); 
if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length); 
} 
return null; 
} 

/* the top navbar images are semi hardcoded into the html from icm, 
 * so some javascript to rewrite the directory  it gets the files from.
 * 
 */
function rewriteToplevelnavImages(style)
{
	var prefix="";
	switch (style)
	{
		case "bonw":
			prefix="negative/";
			break;
		case "yonb":
			prefix="yellow/";
			break;
		case "default":
			prefix=pathmod;
			break;
	}
	
	
	
	//check every image on the page, if its a common image, but not a topnav image
	//put the prefix into the src
	var pageImages=document.getElementsByTagName("img");
	for (var n=0;n<pageImages.length;n++){
		if ((pageImages[n].src.indexOf("common")!=-1)&&(pageImages[n].src.indexOf("/topnav/")==-1)){
			tail=pageImages[n].src.split("/");
			pageImages[n].src="images/common/"+prefix+tail[tail.length-1];						
		}
	}
	
	//change images in form inputs
	var pageImages=document.getElementsByTagName("input");
	for (var n=0;n<pageImages.length;n++){
		if (pageImages[n].src.indexOf("common")!=-1){
			tail=pageImages[n].src.split("/");
			if (pageImages[n].src.indexOf("/topnav/")!=-1){
				pageImages[n].src="images/common/"+prefix+"topnav/"+tail[tail.length-1];
			}
			else{
				pageImages[n].src="images/common/"+prefix+tail[tail.length-1];
			}
		}
	}
	
		
	//current nav image shouldn't be changed on mouseover/out
	var currentnav=document.getElementById("toplevelnavimagecurrent");
	if (currentnav!=null) //check a nav page is actually highlighted
	{
		var tail=currentnav.src.split("/");
		currentnav.src="images/common/"+prefix+"topnav/"+tail[tail.length-1];
	}
	
	
	
	var images=document.getElementsByName("toplevelnavimage");
	for (var n=0;n<images.length;n++)
	{
		var tail=images[n].src.split("/topnav/");
		var newsrc="images/common/"+prefix+"topnav/"+tail[1];

		
		images[n].src=newsrc;	//change the default image		
		//change the mouseover and mouseout images in a way that we don't need to care 
		//about the full uri of the image
		images[n].onmouseover=function(event){
			this.src=this.src.replace(".gif","_on.gif");
		};
		
		images[n].onmouseout=function(event){
			this.src=this.src.replace("_on.gif",".gif");
		};
		
	}
	
	
}