function weskaRollover() {
	if(document.getElementsByTagName) {
		var images = document.getElementsByTagName("img");
		var imgObj = new Image();

		for(var i=0; i < images.length; i++) {
			if(images[i].getAttribute("src").match("_off")) {
				images[i].onmouseover = function() {
					this.setAttribute("src", this.getAttribute("src").replace("_off", "_on"));
				}
				images[i].onmouseup = function() {
					this.setAttribute("src", this.getAttribute("src").replace("_on", "_off"));
				}
				images[i].onmouseout = function() {
					this.setAttribute("src", this.getAttribute("src").replace("_on", "_off"));
				}
				imgObj.src = images[i].getAttribute("src").replace("_off", "_on");
			}
		}
	}
}

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