function checkBrowserName(name){  
   var agent = navigator.userAgent.toLowerCase();  
   if (agent.indexOf(name.toLowerCase())>-1) {  
     return true;  
   }  
   return false;  
 }  

 
sfHover = function() {
if(checkBrowserName('MSIE')){
 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"), "");
  }
 }
}
}