title: The jQuery addClass function quits my script
body: <p>Uhm, I've got <a href="http://jsfiddle.net/gfGTE/" rel="nofollow" title="this script">this script</a> but it does not work.</p>
  
  <p>It's all about this line: <code>document.getElementById('thetest').addClass('superspecial');</code></p>
  
  <p>As soon as the class should be added (but it isn't) the whole script quits...
  Does anybody know why?</p>