I'm upgrading v7.2 to v11.1 and I'm facing a problem with using WebAsyncRefreshPanel.

btnGet Click Event doesn't work on v11.1.

please help.

      <igmisc:WebAsyncRefreshPanel ID="WebAsyncRefreshPanel2" runat="server" TriggerControlIDs="btnGet" RefreshTargetIDs="txtCUS_RCV_NO">
      <table>
            <tr>
                <td>
                    <asp:TextBox ID="txtCUS_RCV_NO" runat="server"></asp:TextBox>
                    <asp:Button ID="btnGet" runat="server" OnClick="btnGet_Click" />
                </td>
            </tr>
      </table>
      </igmisc:WebAsyncRefreshPanel>