title: Ext.LoadMask stays in background of the loading panel
body: <p>I try to show a loading mask while user waits for the panel to be shown.</p>
  
  <p>I use Ext.LoadMask like :</p>
  
  <pre><code>loadingMask = new Ext.LoadMask(Ext.getBody(), {msg:"Loading..."});
  
  loadingMask.show();
  panel = new MyPanel();
  panel .show();
  </code></pre>
  
  <p>and in panel's afterrender </p>
  
  <pre><code>this.listeners = {
          afterrender: function () {
          loadingMask.hide();
          }
  }
  </code></pre>
  
  <p>But no loading mask is shown till panel comes and when I close panel I see the loading Mask.</p>
  
  <p>I think this means my loading mask is running in background so I can't see it.</p>
  
  <p>Is there solution you know for this issue ? This seems like a layer problem I think.</p>
  
  <p>How can I make loading mask be shown on top and in panel's afterrender hide it?</p>
  
  <p>Thank you.</p>