title: Displaying Ext.Window buttons based on condition
body: <p>I have a window like this.</p>
  
  <pre><code>function showDesignWindow(htmlData){
  
     var designWindow =  new Ext.Window({
          title: "E-Form Design",  
          width:650, 
          autoHeight: true,
          id:'designWindow',
          html: htmlData,
          closable: false,
          modal: true,
          y: 150,
          listeners: { 
              beforeclose: function () { 
                  searchVisible = false;                      
              } 
          },
          buttons: [
                   { 
                       text: 'Add Control', handler: function() {
                          saveFormControl();
                       }
                   },
                   {
                       text:'Customize E-Form', handler: function() {                     
                          callCustomWindow();
                          designWindow.close();   
                       }
                   },
                   {
                       text:'Close', handler: function() {
                         designWindow.close();                        
                       }
                   }
                  ]   
    });
  
     designWindow.show(this);
  </code></pre>
  
  <p>}</p>
  
  <p>My Requirement Is I have to display the button 'Customize E-Form' only atleast one control added to the form. So How can i display the Ext.window button based on condition?
  Please suggest me...</p>
  
  <p>Thanks in advance.</p>
  
  <p>-sathya</p>