function ad_728x90(){  
  var script = document.createElement('script');
  randomstr = new String (Math.random());
  randomstr = randomstr.substring(1,8);  
  script.setAttribute( 'type', 'text/javascript' ); 
  script.setAttribute( 'src', '/fra_ad_728x90.php?id=');  
  var head = document.getElementsByTagName('head').item(0);
  head.insertBefore( script, head.firstChild ); 
};

function addEvent(obj, evType, fn){ 
 if (obj.addEventListener){ 
   obj.addEventListener(evType, fn, false); 
   return true;
 } else if (obj.attachEvent){ 
   var r = obj.attachEvent("on"+evType, fn); 
   return r;
 } else {
   return false;
 } 
}             
addEvent(window, 'load', ad_728x90);