var imgRollover = {
	clName: "imgover",
	rpStr: "_on",
	init: function(){
		imgRollover.set_act(document.getElementsByTagName("img"));
		imgRollover.set_act(document.getElementsByTagName("input"));
	},
	set_act: function(imgArray){
		var re = new RegExp("(^|[' '])" + imgRollover.clName + "($|[' '])" ,"i");
		for(var i = 0; i < imgArray.length; i++){
			if(re.test(imgArray[i].className)){
				var hsrc = imgArray[i].getAttribute("src").replace(/\.(jpg|gif|png)/, imgRollover.rpStr + "\.$1");
				var plImg = new Image();
				plImg.src = hsrc;
				imgArray[i].setAttribute("hsrc", hsrc);
				imgRollover.set_evt(imgArray[i]);
			}
		}
	},
	set_evt: function(elemt){
		elemt.onmouseover = function(){
			this.setAttribute("src", this.getAttribute("hsrc"));
		}
		elemt.onmouseout = function(){
			var re = "/" + imgRollover.rpStr + "\.(jpg|gif|png)/";
			this.setAttribute("src", this.getAttribute("src").replace(eval(re), "\.$1"));
		}
	}
}

if (window.addEventListener) {  /* Firefox,Safari,Opera */
	window.addEventListener("load", imgRollover.init, false);
}
else if (window.attachEvent) {  /* IE4, IE5, IE6, IE7 */
	window.attachEvent("onload", imgRollover.init);
}
else if (document.getElementById || document.all) { /* その他DOM準拠 */
	window.onload = imgRollover.init;
}