<head></head><head></head><body onload="test()">
  <pre>Script failed to run.</pre>
  <script>
   function test() {
     alert(document.getElementsByTagName('PRE')[0].firstChild.data =
       document.documentElement.innerHTML);
   }
   var head1 = document.createElement('head');
   document.documentElement.insertBefore(head1, document.documentElement.firstChild);
//   var head2 = document.createElement('head');
//   document.documentElement.appendChild(head2);
//   document.documentElement.appendChild(document.body);
  </script>

</body>