function setRollOvers(tagName, className, over_img_dir) {
			var allImages = document.getElementsByTagName(tagName);
			var loopLength = allImages.length;
			for(var i = 0; i < loopLength; i++) {
				if(allImages[i].className == className) {
					var src = allImages[i].getAttribute('src');
					var underSrc = src;
					//var fileType = src.substring(src.lastIndexOf('.'), src.length);
					//var overSrc = src.replace(fileType, '_over' + fileType);
					
					var fileName = src.substr(src.lastIndexOf('/'), src.length);
					var overSrc = src.replace(fileName, "/" + over_img_dir + fileName);
					var fileType = overSrc.substring(overSrc.lastIndexOf('.'), overSrc.length);
					var overSrc = overSrc.replace(fileType, '_over' + fileType);
					
					var myImage = new Image();
					myImage.src = overSrc;
					
					allImages[i].setAttribute('undersrc', underSrc);
					allImages[i].setAttribute('oversrc', overSrc);
					
					allImages[i].onmouseover = function() {
						this.setAttribute('src', this.getAttribute('oversrc'));
					}	
			
					allImages[i].onmouseout = function() {
						this.setAttribute('src', this.getAttribute('undersrc'));
					}
				}
			}
		}
		
		//document.execCommand("BackgroundImageCache", false, true);