Event.observe(window, "load", function() {
	if (!document.getElementById) 
		return;
	var nodes = document.getElementsByClassName("rollover");
	if (nodes.length) {
		for (var i = 0; i < nodes.length; i++) {
			Event.observe(nodes[i], "mouseover", function() {
				if (!/\-on/.test(this.getAttribute("src"))) {
					var src = this.getAttribute("src");
					var suffix = src.substring(src.lastIndexOf('.'), src.length);
					this.setAttribute("src", src.replace(suffix, "-on" + suffix));
				}
			}, false);
			Event.observe(nodes[i], "mouseout", function() {
				this.setAttribute("src", this.getAttribute("src").replace("-on", ""));
			}, false);
		}
	}
}, false);