asp.net 这段代码老是报An extender can't be in a different UpdatePanel than the control it extends

[gdmm919705]

<asp:UpdatePanel ID="UpdatePanel3" runat="server">
                            <ContentTemplate>
                        发送对象： 
                        <asp:TextBox ID="txtToUser" runat="server" BorderStyle="Solid" BorderWidth="1px">
                        </asp:TextBox>
                         
                        <asp:CheckBox ID="cbPrivateOrPublicChat" runat="server" Text="是否私聊" OnCheckedChanged="cbPrivateOrPublicChat_CheckedChanged"
                            AutoPostBack="True" />
                        <br />
                        内容：
                        <asp:TextBox ID="txtChatMessage" runat="server" BorderColor="Black" BorderStyle="Solid"
                            BorderWidth="1px" Height="56px" TextMode="MultiLine" Width="490px">
                        </asp:TextBox> 
                        <asp:Button ID="btnSubmit" runat="server" OnClick="btnSubmit_Click" Text="提交" />
                        </ContentTemplate>
                        </asp:UpdatePanel>

[pc_funning]

是和模板页冲突的缘故，目前没发现啥有效解决办法