title: Update Panel duplicating my controls
body: <p>My code looks like this:</p>
  
  <pre><code>    &lt;asp:UpdatePanel ID="UpdatePanel1" runat="server"&gt;
      &lt;Triggers&gt;
      &lt;asp:AsyncPostBackTrigger ControlID="btnAddIsotope" EventName="Click" /&gt;
      &lt;/Triggers&gt;
      &lt;ContentTemplate&gt;
      &lt;asp:gridview id="gwResults" runat="server"&gt;
      'all gridview columns go here
      &lt;/asp:gridview&gt;
  
      &lt;asp:ObjectDataSource here&gt;
  
      &lt;asp:Panel id="pnlAddIso" runat="server"&gt;
  
      &lt;asp:Textbox ID="txtIsoDate" runat="server"   /&gt;
      &lt;asp:Button ID="btnAdd"   Text="Add " CssClass="button" runat="server" /&gt;
  
      &lt;/asp:Panel&gt;
  &lt;/ContentTemplate&gt;
      &lt;/asp:UpdatePanel&gt;
  </code></pre>
  
  <p>when i click the button, its supposed to add an item fromt he txtIsoDate into the database and refresh the gridview.</p>
  
  <p>it adds fine, but when it comes back it creates another copy of my pnlAddIso.</p>
  
  <p>why is this happening? i'm so confused. please help.</p>
  
  <p>if im my button i write pnlAddIso.visible=false, the new duplicate panel does not appear, but the old one does not work anymore....</p>