Can I target an element before it's closed?

<body>
 $("body").addClass("active");
 ...
</body>

<body>
   <div id='topStories'></div>
   <script type='text/javascript'>
     $('div#topStories').addClass('active');
   </script>
</body>

<html>
<head>
    <style type="text/css">
    	.foobar { background-color: #CCC; }
    </style>
</head>
<body>
    <script type="text/javascript">
    	window.document.body.className = "foobar";
    </script>
    <div style="border: solid 1px"><br /></div>
    <script type="text/javascript">
    // happens before DOM is fully loaded:
    	alert(window.document.body.className);
    </script>
    <span>Appears after the alert() call.</span>
</body>
</html>

<script>
  $(document).ready(function() {
    $("body").addClass("active");
  });
</script>
<body>
  ..
  ..
  ..
</body>

<body class="active">
</body>

<script type="text/javascript">
    document.documentElement.className = 'active';
</script>