d();
        } else $('mouseenter').passed();
        
        $('mouseenter').stopObserving();
      });
    });
  </script>
  
  <p id="addunload">Add unload events</p>
  
  <script type="text/javascript">
    $('addunload').observe('click', function(e){
      if (this._done) return;

      window.onunload = function(){ alert('inline unload fired!') }
      Event.observe(window, 'unload', function(event){
        if (!event.target) {
          alert('FAILURE: event.target should not be null!');
        }
