title: showing an asp:ModalPopupExtender using jQuery
body: <p>I am trying to show an asp:ModalPopupExtender using jQuery, without any success. Here is what I have :</p>
  
  <p><strong>ASP.NET</strong></p>
  
  <pre><code>&lt;asp:ModalPopupExtender BehaviorID="confirmPopup" ID="confirmPopup" runat="server" /&gt;
  </code></pre>
  
  <p><strong>JAVASCRIPT</strong></p>
  
  <pre><code>function ShowConfirmPopup() {
      var _id = '#&lt;%= confirmPopup.ClientID %&gt;';
      var modal = $find(_id);
      modal.show();
  }
  </code></pre>
  
  <p>What happens is that <code>modal</code> is always equal to <code>null</code>, so the popup never gets shown. What am I doing wrong?</p>