title: Dojo dialog close event on X (top-right)
body: <p>Im using Dojo to create a simple dialog to create a user in a system. The problem is I get the error: </p>
  
  <pre><code>Tried to register widget with `id==user_submit` but that `id` is already registered
  </code></pre>
  
  <p><code>user_submit</code>, is a Dojo button I have to finish the form inside the dialog. When I close the dialog by clicking it and submitting the form there is no problem in opening the dialog again (in the click event on the button I have this line of code:</p>
  
  <pre><code>dijit.byId("user_submit").destroy();
  </code></pre>
  
  <p>but if I close the dialog through the [x]-link / button in the top-right corner I don't destroy the button and then can't open the dialog again without reloading the page.</p>
  
  <p>How do I get Dojo to destroy the button or how to a overload the click-event on [X]-link / button, so I can write the destroy command for the button?</p>