title: JS Tweenlite onCompleteParams sending null
body: <p>doing a looped tween in Javascript runs just twice and then stops. in the debugger i can see that a Null value is sent after the 2nd time.</p>
  
  <p>Any ideas how to fix this, or is it a bug with the Greensock library?</p>
  
  <pre><code> TweenLite.to(box, 2, {left:Math.random() * 600,onComplete:completeHandler, onCompleteParams:box});
  
  
  function completeHandler(obj) {
  if (obj)
    TweenLite.to(obj, 2, {left:Math.random() * 600,onComplete:completeHandler, onCompleteParams:obj});
  }
  </code></pre>