hoverb = function() {
    var sdmMenu = document.getElementById("nav").getElementsByTagName("li");
    for (var i=0; i<sdmMenu.length; i++) {
      sdmMenu[i].onmouseover=function() { this.className+=" hoverb"; }
      sdmMenu[i].onmouseout=function() { this.className=this.className.replace(new RegExp(" hoverb\\b"), ""); }
    }
  }
  if (window.attachEvent) window.attachEvent("onload", hoverb);