version = navigator.appVersion.toLowerCase();
agent = navigator.userAgent.toLowerCase();
ie = (version.indexOf('msie')>-1);
ie50 = (version.indexOf('msie 5.0')>-1);
win = (version.indexOf('windows')>-1);
opera = (agent.indexOf('opera')>-1);

startList = function() {
if ((ie50) && (win)) return false;
else if (document.all&&document.getElementById) {
navRoot = document.getElementById("dropdown");
for (i=0; i<navRoot.childNodes.length; i++) {
node = navRoot.childNodes[i];
if (node.nodeName=="LI") {
node.onmouseover=function() {
this.className+=" over";
  }
  node.onmouseout=function() {
  this.className=this.className.replace(" over", "");
   }
   }
  }
 }
}
window.onload=startList;