var sfHover = function() 
{	
	var sfEls = document.getElementById("dropnav").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);