function smartRollover(){
	if(document.getElementsByTagName){
		var images = document.getElementsByTagName("img");

		for(var i=0;i < images.length;i++){
			if(images[i].getAttribute("src").match("_off.")){
				images[i].onmouseover = function(){
					this.setAttribute("src",this.getAttribute("src").replace("_off.","_on."));
				}
				images[i].onmouseout = function(){
					this.setAttribute("src",this.getAttribute("src").replace("_on.","_off."));
				}
			}
		}
	}
}
if(window.addEventListener){
	window.addEventListener("load",smartRollover,false);
}else if(window.attachEvent){
	window.attachEvent("onload",smartRollover);
}