function addClass(el, classname) {
	var re = new RegExp('( ?\\b' + classname + '\\b|$)');
	el.className = el.className ? el.className.replace(re, ' ' + classname) : classname;
	return el;
}

function removeClass(el, classname) {
	var re = new RegExp(' ?\\b' + classname + '\\b', '');
	el.className = el.className.replace(re, '');
	return el;
}

sfHover = function() {
	var sfEls = document.getElementById("nav").getElementsByTagName("LI");
	for (var i=0; i<sfEls.length; i++) {
		sfEls[i].onmouseover=function() {
			addClass(this, 'sfhover');
		}
		sfEls[i].onmouseout=function() {
			removeClass(this, 'sfhover');
		}
	}
}

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

if(window.addEventListener) {
	window.addEventListener("load", sfHover, false);
}