Updatepanel无法在第二次点击时工作？

Question

嗨朋友在我的联系我们页面即时通讯使用updatepanel.when我点击按钮它会将详细信息存储在database.on第一次按钮点击它工作正常。第二次点击更新面板不工作..任何人都可以帮助我...我的来源...... ...

<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server">
    <ContentTemplate>
        <div class="form">
            <form action="#">
            <div class="fields">
                <div style="width: 178px; height: 55px" class="column">
                    <p class="label">
                        Name<span>
                            <asp:RequiredFieldValidator ID="rfv1" runat="Server" ErrorMessage="*" ControlToValidate="txtname">
                            </asp:RequiredFieldValidator>
                        </span>
                    </p>
                    <p>
                        <span></span>
                    </p>
                    <div style="width: 180px" id="DIV1">
                        <asp:TextBox ID="txtname" runat="server" Height="30px" Width="175px">
                        </asp:TextBox></div>
                </div>
                <div style="width: 178px; height: 57px" class="column">
                    <p class="label">
                        E-mail<span>
                            <asp:RequiredFieldValidator ID="rfv2" runat="Server" ErrorMessage="*" ControlToValidate="txtmail">
                            </asp:RequiredFieldValidator>
                            <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" ErrorMessage="*"
                                ControlToValidate="txtmail" ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"></asp:RegularExpressionValidator></span></p>
                    <p>
                        <span></span>
                    </p>
                    <div style="width: 180px">
                        <asp:TextBox ID="txtmail" runat="server" Height="30px" Width="175px"></asp:TextBox></div>
                </div>
                <div style="width: 181px; height: 9px" class="column">
                    <p class="label">
                        Subject</p>
                    <p>
                        <span></span>
                    </p>
                    <div style="width: 180px">
                        <asp:TextBox ID="txtsubject" runat="server" Height="30px" Width="180px"></asp:TextBox></div>
                </div>
            </div>
            <p class="label">
                Message<span>
                    <asp:RequiredFieldValidator ID="rfv3" runat="Server" ErrorMessage="*" ControlToValidate="txtmessage">
                    </asp:RequiredFieldValidator></span></p>
            <p>
                <span></span>
            </p>
            <div style="width: 93%; height: 146px" id="DIV2">
                <asp:TextBox ID="txtmessage" runat="server" Height="130px" Width="577px" TextMode="MultiLine">
                </asp:TextBox></div>
            <asp:Button ID="btnSubmit" OnClick="btnSubmit_Click" runat="server" Text="Send Message"
                CssClass="general_button blue"></asp:Button>
            <asp:Label Style="z-index: 100; left: 58px; position: absolute; top: 893px" ID="Label1"
                runat="server" Visible="False" Text="Label"></asp:Label>
            <asp:Label ID="Label2" runat="server" Width="436px" Visible="False" Text="Label"
                Font-Bold="True" ForeColor="DarkGreen"></asp:Label>
            </form>
        </div>
    </ContentTemplate>
    <Triggers>
        <asp:AsyncPostBackTrigger ControlID="btnSubmit" EventName="Click" />
    </Triggers>
</asp:UpdatePanel>