sfHover = function() {
    var topnav = document.getElementById("topnav")
    if (topnav != null)
    {
	    var sfEls = topnav.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 (Behaviour.addLoadEvent) Behaviour.addLoadEvent(sfHover);