function Rollover() {
	if(document.getElementsByTagName) {
		var images = document.getElementsByTagName("img");
		for(var i=0; i < images.length; i++) {
			SetRollover(images[i]);
		}
	}
}
function SetRollover(elm) 
{
	if(elm.getAttribute("src").match("_off."))
	{
		elm.onmouseover = function() {
			this.setAttribute("src", this.getAttribute("src").replace("_off.", "_on."));
		}
		elm.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);
}