title: Extjs add div into a window
body: <p>i would like to add a new div tag by clicking a button, but it doesnt work.
  I have a web desktop from extjs and two modules. One window like the following code, with 1 div [20,20]. And a second window with a button and handler to add a new div tag in the first window. But it doesnt work.</p>
  
  <pre><code>            win = desktop.createWindow({
              id: 'firstwindow',
              title: 'firstwindow',
              width: 421,
              height: 391,
              divs: [{
                  x: 20,
                  y: 20
              }],
  </code></pre>
  
  <p>and so on..</p>
  
  <p>and here the code for adding a div in the firstwindow by clicking button in the second window</p>
  
  <pre><code>                handler: function(){
                      if (Ext.getCmp('firstwindow')) {
  
                          Ext.getCmp('firstwindow').add({
                              divs: [{
                                  x: 20,
                                  y: 40
                              }] 
                          })
                          Ext.getCmp('firstwindow').render();
                          console.log(Ext.getCmp('firstwindow'));
                      }
                  }
  </code></pre>
  
  <p>Thanks in advance,
  cheers,
  Thomas</p>