title: Window is not a constructor error?
body: <p>I have this code in a JavaScript file:</p>
  
  <pre><code>this.tooltipWindow = new Window("__tooltip__", TooltipManager.options);
  </code></pre>
  
  <p>This gives me the <code>TypeError: Window is not a constructor</code> error in Firefox. Is there something wrong with this code and yes, how can I rewrite it, so it works?</p>
  
  <p>Thanks!</p>