title: Refresh jquery ui dialog position
body: <p>I'm using a jquery dialog.
  The content of this dialog is dynamic so the height change when the dialog is open.</p>
  
  <pre><code>$("#a_div").dialog({ width: 400 });
  </code></pre>
  
  <p>The dialog initially appears center in the page. but when the height change is no more center.</p>
  
  <p>How can i refresh the dialog's position without close and reopen it?</p>
  
  <p>thanks</p>