function Rollover() {
	if(document.getElementsByTagName) {
		var image = document.getElementsByTagName("img");

		for(var i=0; i < image.length; i++) {
			if(image[i].getAttribute("src").match("off."))
			{
				image[i].onmouseover = function() {
					this.setAttribute("src", this.getAttribute("src").replace("off.", "on."));
				}
				image[i].onmouseout = function() {
					this.setAttribute("src", this.getAttribute("src").replace("on.", "off."));
				}
			}
		}
	}
}

if(window.addEventListener) {
	window.addEventListener("load", Rollover, false);
}
else if(window.attachEvent) {
	window.attachEvent("onload", Rollover);
}