var allImages = document.getElementsByTagName("img");
for (var i=0; i<allImages.length; i++){
	if(allImages[i].className=="rolloverButton"){
		(new Image()).src = allImages[i].src.replace("OFF","OVER"); // cache the images to improve rollover response time
		allImages[i].onmouseover = function(){
			this.src = this.src.replace("OFF","OVER");
			return true;
		}
		allImages[i].onmouseout = function(){
			this.src = this.src.replace("OVER","OFF");
			return true;
		}
	}
}