function imageReplace(){
	var btnClassName = "btn";
	var objAll = document.getElementsByTagName ? document.getElementsByTagName("*") : document.all;
	for (var i = 0; i < objAll.length; i++) {
		var btn=false;
		var eltClass = objAll[i].className.split(/\s+/);
		for (var j = 0; j < eltClass.length; j++) {
			if (eltClass[j] == btnClassName)btn = true;
		}
		if(btn == true){
			if(objAll[i].originalSrc){
				objAll[i].rolloverSrc = objAll[i].originalSrc.replace(/(\.gif|\.jpg|\.png)$/,"_on$1");
					objAll[i].onmouseover = function(){
						this.style.filter ="progid:DXImageTransform.Microsoft.AlphaImageLoader(src="+this.rolloverSrc+",sizingMethod='scale')";
					}
					objAll[i].onmouseout = function(){
						this.style.filter ="progid:DXImageTransform.Microsoft.AlphaImageLoader(src="+this.originalSrc+",sizingMethod='scale')";
					}
			}else{
				if(objAll[i].nodeName=="IMG"){
					objAll[i].originalSrc = objAll[i].src
					objAll[i].rolloverSrc = objAll[i].src.replace(/(\.gif|\.jpg|\.png)$/,"_on$1")
					objAll[i].onmouseover = function(){
						this.src = this.rolloverSrc;
					}
					objAll[i].onmouseout = function(){
						this.src = this.originalSrc;
					}
				}
			}
		}
	}
}

function addEvent(elm,listener,fn){
	try{
		elm.addEventListener(listener,fn,false);
	}catch(e){
		elm.attachEvent("on"+listener,fn);
	}
}
function preLoad() {
	var imgAry = new Array();
	for(i=0;i<$(".btn").length;i++){
		if(undefined != $(".btn:eq(" + i + ")").attr("src")){
			src = $(".btn:eq(" + i + ")").attr("src");
			src = src.substring(0 , src.length - 4) + "_on" + src.substring(src.length - 4);
			imgAry[i] = new Image();
			imgAry[i].src = src;
		}
	}
}
addEvent(window,"load",imageReplace);