title: Customize Ext.window.MessageBox ExtJS 4
body: <p>Im using Ext.window.MeassageBox for confirmation dialog window.</p>
  
  <p>Code is something like this:</p>
  
  <pre><code>deleteSomething: function( grid, row, col ) {
      var ids = [ grid.store.getAt( row ).get( 'id' ) ];
  
      function deleteSomething ( btn, text ) {
          if( btn === 'yes' ) {
              Ext.Ajax.request( {
                  url: 'data/deleteSomething.php',
                  params: {
                      'ids': Ext.encode( ids )
                  },
                  success: function( response ) {
                      //perform some actions
                  }
              } );
          }
      }
  
      Ext.MessageBox.show( {
          animEl: 'elId',
          buttons: Ext.MessageBox.YESNO,
          fn: deleteSomething,
          msg: Locale.gettext( 'Are you sure you want to remove the selected thing?' ),
          title: Locale.gettext( 'Delete?' )
      } );
  }
  </code></pre>
  
  <p>I want to apply some css rules for message field and <strong>scale: 'medium'</strong> with right-side align for buttons. Is there any way to achive it without extend MessageBox?</p>