title: ExtJs add panel as tab item
body: <p>I have a <a href="http://pssnet.com/~devone/pssops3/home4.php" rel="nofollow noreferrer">setup</a> where the tab is expected to be loaded based on user selection of an item from a left panel tree.  My objective is to load only the relevant items as per the user selection to a particular tab. </p>
  
  <p>The first time, I am able to add item as below:</p>
  
  <pre><code>    var tab = tabs1.getItem('Orders');   
      tab.remove(0);
      tab.add(pane33);
      tab.doLayout(); 
  </code></pre>
  
  <p>But, when the user selects the item again, the panel item is already removed, and errors out as (<code>c.getPositionEl().dom is undefined</code>).  </p>
  
  <p>The error is due to the item being removed or destroyed.  There seems no option to replace the tab item, or to refresh/reload panels.  </p>
  
  <p>How to handle this?</p>
  
  <p>Thanks.</p>