function rollover2() {
	if (!document.getElementsByTagName) return false;
	var image = document.getElementsByTagName("img");
	for (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.","_ov."));
	 		}
	 		image[i].onmouseout = function() {
	 			this.setAttribute("src", this.getAttribute("src").replace("_ov.","_off."));
	 		}
		}
	}
}

function addLoadEvent(func) {
	var oldonload = window.onload;
	if (typeof window.onload != 'function') {
		window.onload = func;
	}else {
		window.onload = function() {
		oldonload();
		func();
		}
	}
}

addLoadEvent(rollover2);