function initRollovers() {
	if (!document.getElementById) return
	var aPreLoad = new Array();
	var sTempSrc;
	var targetImg = $$(".on");
	targetImg.each(function(obj){
		var src = obj.getAttribute('src');
		var ftype = src.substring(src.lastIndexOf('.'), src.length);
		var hsrc = src.replace(ftype, '_on'+ftype);
		var onImg = new Image();
		onImg.src = hsrc;
		
		obj.observe("mouseover", function(){
			obj.setAttribute('src', hsrc);
		});
		obj.observe("mouseout", function(){
			obj.setAttribute('src', src);
		});
	});
}

addEvent(window,"load",function(){
	initRollovers();
});