<!DOCTYPE html>
<!-- form with no elements and invalid element is added dynamically -->
<html>
  <head>
    <style>
      form:invalid { display:none }
    </style>
    <script>
      function onLoadHandler()
      {
        document.forms[0].appendChild(document.getElementById('i'));
        document.documentElement.className='';
      }
    </script>
  </head>
  <body onload='onLoadHandler();'>
    <input id='i' required>
    <form>
    </form>
  </body>
</html>
