function addEvent(obj, evType, fn) {
	if(obj.addEventListener) {
		obj.addEventListener(evType, fn, true);
		return true;
	} else if(obj.attachEvent) {
		var r = obj.attachEvent('on' + evType, fn);
		return r;
	} else {
		return false;
	}
}

sfHover = function() {
	if(!document.defaultView) { // ie only
		var sfEls = document.getElementById('mainNav').getElementsByTagName('li');
		for(var i = 0; i < sfEls.length; i++) {
			sfEls[i].onmouseover = function() {
				this.className += ' sfHover';
			}
			sfEls[i].onmouseout = function() {
				this.className = this.className.replace(new RegExp(' sfHover\\b'), '');
			}
		}
	}
}

addEvent(window, 'load', sfHover);