title: UpdatePanel inside a bootstrap modal doesn't update
body: <p>I change the label's text that resides with a UpdatePanel that is within a Bootstrap Modal. When the Modal pops up, the text has not been set (through in debugging I can see it sets the labels text correctly with the error message).</p>
  
  <p>This modal resides and is called from within a UserControl. </p>
  
  <p>What am I missing? Why isn't the UpdatePanel being triggered?</p>
  
  <pre><code>&lt;%--ERROR MODAL--%&gt;
  &lt;asp:Panel runat="server" class="modal fade" ID="modalErrorMessage" role="dialog" aria-labelledby="modalErrorMessage" aria-hidden="true"&gt;
  &lt;div class="modal-dialog"&gt;
      &lt;asp:UpdatePanel runat="server"&gt;
          &lt;ContentTemplate&gt;
              &lt;div class="modal-content panel-danger"&gt;
                  &lt;div class="modal-header panel-heading"&gt;&lt;span class="glyphicon glyphicon-warning-sign" aria-hidden="true"&gt;&lt;/span&gt; Error!&lt;/div&gt;
                  &lt;div class="modal-body"&gt;
                      &lt;asp:Label runat="server" ID="lblmodalErrorMessage" Text=""&gt;&lt;/asp:Label&gt;
                      &lt;br /&gt;
                      &lt;div class="modal-footer margin-top-sm"&gt;
                          &lt;asp:Panel runat="server" ID="Panel2"&gt;
                              &lt;button type="button" class="btn btn-default" data-dismiss="modal"&gt;Close&lt;/button&gt;
                          &lt;/asp:Panel&gt;
                      &lt;/div&gt;
                  &lt;/div&gt;
              &lt;/div&gt;
          &lt;/ContentTemplate&gt;
      &lt;/asp:UpdatePanel&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p></p>
  
  <pre><code>    Private Sub RaiseErrorMessageModal(errorMessage As String)
          lblmodalErrorMessage.Text = errorMessage
          RegisterModalPopup(modalErrorMessage.ClientID)
      End Sub
  
  
  
      Protected Sub RegisterModalPopup(modalId As String)
          Dim script = String.Format("$('#{0}').modal();", modalId)
          ScriptManager.RegisterStartupScript(Page, Page.GetType(), modalId,
                                              script, True)
      End Sub
  </code></pre>