title: Check whether some element is "focused" without jQuery
body: <p>I was almost sure I could find the answer here, but I wasn't successful.
  How would you check whether is there some object selected (focused) on the moment of the event call? I tried <code>if (document.activeElement == "[object HTMLBodyElement]")</code>, but apparently the <code>.activeElement</code> is being filled onLoad. I am not allowed to use jQuery, only mootools.</p>
  
  <p>Thanks a lot for the help!</p>