sfHover = function() {
        var sfEls = document.getElementById('nav').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'),'');
                }
        }
}
if (window.attachEvent) window.attachEvent('onload',sfHover);