title: Sending java script variable value as part of PostBackUrl query string
body: <p>I need to send a parameter value into a query string of a PostBackUrl method
  within asp button.</p>
  
  <p>The value I need is already being captured within a java script function shown below.</p>
  
  <p>How do I send the value in hiddId as part of URL ? The below method isn't working. Can someone please help ?</p>
  
  <pre><code>   &lt;script language="javascript" type = "text/javascript"&gt;
          function btn_Selected() {
             var hiddId = null;
             $('#&lt;%=GridView1.ClientID %&gt;').find('input[type=radio]:checked').each(function () {
                 hiddId = $(this).closest('tr').find('input[type = "hidden"]').val();
             });
  
       }
  
   &lt;asp:Button ID="Btn_Update" runat="server" Text="Update" PostBackUrl="Screen_Edit.aspx?CustID='&lt;%=hiddId%&gt;'"
  </code></pre>