title: How to override the event handlers of built-in controls and its visibility in VSTO Outlook addin 2010
body: <p>I have created a custom group with a toggle button in built-in 'TabAppointment' tab, where clicking on the button will open a new winform.</p>
  
  <p>Only after proceeding with that form, 'Save&amp;Close' button should be enabled in the appointment screen.</p>
  
  <p>But iam not able to disbale the built-in controls, i have tried as like below</p>
  
  <pre><code>    &lt;?xml version="1.0" encoding="UTF-8"?&gt;
      &lt;customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui" onLoad="Ribbon_Load"&gt;
        &lt;ribbon&gt;
          &lt;tabs&gt;
            &lt;tab idMso="TabAppointment"&gt;
              &lt;group idMso ="GroupActions"&gt;
                &lt;button idMso="SaveAndClose" getEnabled="GetEnabled"/&gt;
              &lt;/group&gt;
              &lt;group id="GroupRBS" insertBeforeMso="GroupActions" label="RBS"&gt;
                &lt;toggleButton id="btnBookRoom" label ="Add Room" supertip ="Room booking option for an appointment" imageMso="AddRoom" onAction="CallRBS" size="large" getEnabled="GetEnabled" /&gt;
              &lt;/group&gt;
            &lt;/tab&gt;
          &lt;/tabs&gt;
        &lt;/ribbon&gt;
      &lt;/customUI&gt;
  </code></pre>
  
  <p>I have created 'GetEnabled' callback method in ribbon class, but it is firing only for custom group controls, cant we override builtin control attributes?</p>
  
  <p>Iam able to hide builtin groups, but not able to  hide a particular builtin control inside the builtin group, is there any way to do this?</p>
  
  <p>Pls help me for getting ny solution</p>