function cacheImgs(img){
	var cached = new Image();
	cached.src = img;
}

function setRollovers(){
		if(!document.getElementsByTagName) return false;
		var nav_elements = document.getElementsByTagName("a");
		for(var i=0; i<nav_elements.length; i++){

			if(nav_elements[i].className == 'roll_it'){
				nav_elements[i].onmouseover = switchOn;
				nav_elements[i].onmouseout = switchOff;

				var imgToSwap = nav_elements[i].childNodes;

				for(var j=0; j<imgToSwap.length; j++){
					if(imgToSwap[j].nodeType == 1){
						var source 		= imgToSwap[j].src.lastIndexOf('/') + 1;
						var image_path 	= imgToSwap[j].src.substring(0,source);
						var fileSrc 	= imgToSwap[j].src.substring(source);
						var type_spot	= fileSrc.lastIndexOf('.') + 1;
						var filetype	= fileSrc.substring(type_spot);
						var spot 		= (fileSrc.length - 6);
						var newSrc  	= fileSrc.substring(0,spot);
						//alert(image_path + newSrc + 'n.' + filetype);
						cacheImgs(image_path + newSrc + 'n.' + filetype);
					}
				}
			}
		}
}

function switchOn(){
	var imgToSwap = this.childNodes;
	for(var i=0; i<imgToSwap.length; i++){
		if(imgToSwap[i].nodeType == 1){
			var source 		= imgToSwap[i].src.lastIndexOf('/') + 1;
			var image_path 	= imgToSwap[i].src.substring(0,source);
			var fileSrc 	= imgToSwap[i].src.substring(source);
			var type_spot	= fileSrc.lastIndexOf('.') + 1;
			var filetype	= fileSrc.substring(type_spot);
			var spot 		= (fileSrc.length - 6);

			var newSrc  	= fileSrc.substring(0,spot);
			
			if(fileSrc.substr(fileSrc.lastIndexOf('_')+1,3) == 'off'){
				imgToSwap[i].src = (image_path+newSrc + 'n.' + filetype);
			}
		}
	}
}

function switchOff(){
	var imgToSwap = this.childNodes;
	for(var i=0; i<imgToSwap.length; i++){
		if(imgToSwap[i].nodeType == 1){
			var source 		= imgToSwap[i].src.lastIndexOf('/') + 1;
			var image_path 	= imgToSwap[i].src.substring(0,source);
			var fileSrc 	= imgToSwap[i].src.substring(source);
			var type_spot	= fileSrc.lastIndexOf('.') + 1;
			var filetype	= fileSrc.substring(type_spot);
			var spot 		= (fileSrc.length - 5);
			
			var newSrc  	= fileSrc.substring(0,spot);
			
			if(fileSrc.substr(fileSrc.lastIndexOf('_')+1,2) == 'on'){
		        		imgToSwap[i].src = (image_path+newSrc + 'ff.' + filetype);
			}
		}
	}
}

addOnLoadEvent(setRollovers);