function correctMenuIE6(){
if(navigator.appName!='Microsoft Internet Explorer') return;
 var nodes = document.getElementById("mus_top_menu").
                 getElementsByTagName("li");
 for (var i=0; i<nodes.length; i++) {
  nodes[i].onmouseover = function() {
   this.className += " hover";
  }
  nodes[i].onmouseout = function()  {
  this.className = this.className.replace(" hover", "");
  }
 }
}