title: How to get currently active item`s index number (and not active item`s id) on a card layout on Extjs?
body: <p>How do I get the currently active item's index number (and not active item's id) on a card layout?
  The following code will return active item's id:</p>
  
  <pre><code>     Ext.getCmp('my-wizard').getLayout().activeItem.id];
  </code></pre>
  
  <p>What if I don't want to define an id for my component items and I just want to access active item's index number?</p>