How does it call id with html? :    

 ## Heading ##
             <asp:LinkButton ID="lnkDelete" Font-Bold="true" ForeColor="Black"
              runat="server" CommandName="Sil" OnClientClick="OpenPopup('<%#
              Eval("YolcuId") %>')" Text="Sil"/>         
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           function OpenPopup(id)
                   {
                       $('#sill').modal();
                       $('#hfsilId').val(id);
                   }