function sfHover() {
 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"), ""); 
		} 
	} 
}