CheckBox changed event of inner Repeater

asp:Repeater ID="repCategory" runat="server" OnItemDataBound="repCategory_OnItemDataBound">
                                <HeaderTemplate>
                                </HeaderTemplate>
                                <ItemTemplate>
                                    <tr>
                                        <td valign="middle" align="center" width="5%">
                                        </td>
                                        <td colspan="6">
                                            <asp:Repeater ID="repSubCategory" runat="server" OnItemDataBound="repSubCategory_OnItemDataBound">
                                                <HeaderTemplate>
                                                    <table width="100%">
                                                </HeaderTemplate>
                                                <ItemTemplate>
                                                    <tr>
                                                        <asp:Repeater ID="repProduct" runat="server" OnItemDataBound="repProduct_OnItemDataBound">
                                                            <ItemTemplate>
                                                                <td align="left" width="16%">
                                                                </td>
                                                            </ItemTemplate>
                                                        </asp:Repeater>
                                                    </tr>
                                                </ItemTemplate>
                                                <FooterTemplate>
                                                    <tr>
                                                        <asp:Repeater ID="repOrder" runat="server" OnItemCreated="repOrder_OnItemCreated_drdFill">
                                                            <ItemTemplate>
                                                                <td>
                                                                     <asp:CheckBox ID="chkbxOrder" runat="server" />
                                                                    <asp:DropDownList ID="drdListNoOfOrders" runat="server">
                                                                    </asp:DropDownList>
                                                                </td>
                                                            </ItemTemplate>
                                                        </asp:Repeater>
                                                    </tr>
                                                    </table>
                                                </FooterTemplate>
                                            </asp:Repeater>
                                        </td>
                                    </tr>
                                </ItemTemplate>
                                <FooterTemplate>
                                    </table>
                                </FooterTemplate>
                            </asp:Repeater>

protected void repOrder_OnItemCreated_drdFill(object sender, RepeaterItemEventArgs e)
{
  CheckBox chk = (CheckBox)e.Item.FindControl("chkbxOrder");
  chk.CheckedChanged += new EventHandler(CheckedChanged);
}

private void CheckedChanged(object sender, EventArgs e)
{
        CheckBox cb = (CheckBox)sender;
        try
        {
            My Code
        }
        catch (Exception ex)
        {
        }
}