if (navigator.userAgent.indexOf("Opera")!=-1
    && document.getElementById) type="OP"; 
if (document.all) type="IE"; 
if (document.layers) type="NN"; 
if (!document.all && document.getElementById) type="MO"; 

function ShowLayer(id, action){
  if (type=="IE") eval("document.all." + id + ".style.visibility='" + action + "'");
  if (type=="NN") eval("document." + id + ".visibility='" + action + "'");
  if (type=="MO" || type=="OP") 
    eval("document.getElementById('" + id + "').style.visibility='" + action + "'");
} 


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