function addLoadEvent(func) { 
  var oldonload = window.onload; 
  if (typeof window.onload != "function") { 
    window.onload = func; 
  } else { 
    window.onload = function() { 
      if (oldonload) { 
        oldonload(); 
      } 
      func(); 
    }; 
  } 
}