title: extjs type error el is null
body: <p>I've got some odd error which I don't know how to overcome. Here is what I've got for now - one view with button on it, clicking on button will open a new empty window. So, when I'm doing the scenario below, I'm getting <strong>Type error el is null</strong> error. So here is the scenario:</p>
  
  <ol>
  <li>Open main view. </li>
  <li>Click on the button. </li>
  <li>Window is popped up. </li>
  <li>Close popped up window. </li>
  <li><strong>Resize main view.</strong> (without resizing eveything is ok)</li>
  <li>Click on the button. </li>
  <li>Window is not popped up, but object is created and when I'm clicking on the button onу more time I'm getting the error, saying that it's impossible to create objects with similar id's. After Type error el is null error showed nothing is showed or rendered anymore, so this is pretty critical thing.</li>
  </ol>
  
  <p>I saw some topics devoted to such a error, but the solution is not stated anywhere. Here is the <a href="http://www.sencha.com/forum/showthread.php?84363-Render-a-FormPanel-into-div&amp;s=4f3107330d117f29c278fdff1e0195f0" rel="nofollow">topic</a> where forum user <strong><em>Animal</em></strong> talked about this error and, again, solution is not provided overthere.</p>