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);