title: Passing a HiddenField value to a User Control in javascript
body: <p>I have a <code>HiddenField</code> which changes value depending on what the user clicks. On the same page I have an invisible <code>Panel</code> with a <code>User Control</code> inside of it. I want to pass this value to the control when the Panel becomes visible.</p>
  
  <p>The code:</p>
  
  <pre><code>&lt;asp:HiddenField ID="hfdSelectedDeliveryAddressID" runat="server" Value="0" /&gt;
  &lt;asp:Panel ID="pnlOrder" runat="server" Visible="false"&gt;
      &lt;uc3:AddressBook ID="AddressBook1" runat="server" AddressID="[value]" /&gt;
  &lt;/asp:Panel&gt;
  </code></pre>
  
  <p>I guess I'm asking what the syntax is to insert <code>$("#&lt;%= hfdSelectedDeliveryAddressID.ClientID %&gt;").val()</code> where "[value]" is. Help?</p>