function smartRollover() {

	if (document.getElementsByTagName) {

		var images = document.getElementsByTagName("img");

		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].onmouseout = function() {

					this.setAttribute("src", this.getAttribute("src").replace("_on.", "_off."));

				};

			}

		}

	}

}

if (window.addEventListener) {

	window.addEventListener("load", smartRollover, false);

} else if (window.attachEvent) {

	window.attachEvent("onload", smartRollover);

}