<head>
  <script type='text/javascript'>
  <![CDATA[
    function update() {
      var percent = document.getElementById('percent');
      if (percent) {
        percent = parseInt(percent) + 1;
        setTimeout('update()', 1000);
      }
    }
    update();
  ]]>
  </script>
</head>
<body>
  <progress id='percent'>0</progress> %
</body>
