function setPosition() {
 if((navigator.appName=="Netscape" && parseInt(navigator.appVersion.substring(0,1))>=5) ||
     navigator.appName=="Opera" && parseInt(navigator.appVersion.substring(0,1))>=7) {
  document.getElementById("menu").style.position="fixed";
 }

 if(navigator.appName=="Microsoft Internet Explorer") {
  document.getElementById("menu").style.position="absolute";
  document.getElementById("menu").style.top=document.body.scrollTop+150+"px";
  window.setTimeout("setPosition()",1);
 }

 if(navigator.appName=="Netscape" && navigator.appVersion.substring(0,1)=="4") {
  document.menu.top=window.pageYOffset+10;
  window.setTimeout("setPosition()",1);
 }
}