title: Elements of the Viewport EXTJS are not clickable
body: <p>I am reading the book "MasteringExtjs" and Chapter 3 we created a ViewPort
  Ext.create ('Packt.view.MyViewport'), the ViewPort is shown, but the elements (buttons, menus) are not clickable.</p>
  
  <p><a href="http://goo.gl/ymxtwY" rel="nofollow">ViewPort Code</a></p>
  
  <p><a href="https://github.com/loiane/masteringextjs/blob/extjs-4.2.1883/app/controller/Login.js" rel="nofollow">Login Controller</a></p>