nav = function() {
	var els = document.getElementById("nav").getElementsByTagName("li");
	for (var i=0; i<els.length; i++) {
		els[i].onmouseover = function() {
			this.className += " hover";
		}
		els[i].onmouseout = function() {
			this.className = this.className.replace(new RegExp(" hover\\b"), "");
		}
	}
}

if (window.attachEvent) {
	window.attachEvent("onload", nav);
}