title: How do I change the radio button icon in extjs?
body: <p>I have two Ext.menu.CheckItem's in a group. How would I change the checked item's disc icon to something else? I would like to retain the radio button functionality (only one selected), but have a check mark instead of the disc.</p>
  
  <pre><code>var options = new Ext.Button({
      allowDepress: false,
      menu: [
          {checked:true,group:'labels',text:'Option 1'},
          {checked:false,group:'labels',text:'Option 2'}
      ]
  });
  </code></pre>