when I click on the submit button of contact us form . it automatically goes to top of the page . but i want to reload specific part of page

Question

I am developing single page website using asp.net , at bottom of my page I have created contact us form. problem is that when I click on the submit button of contact us form . it automatically goes to top of the page html code is here `

<form id="form1" runat="server">

<div>
    <h2>Contact Us</h2>
    <br />
    <table>
        <!-- Name -->
        <tr>
            <td align="center">
                Name:</td>
            <td>
                <asp:TextBox ID="txtName" 
                                runat="server" BackColor="Transparent"
                                Columns="50"></asp:TextBox>
            </td>
        </tr>

        <!-- Subject -->
        <tr>
            <td align="center">
                Subject:
            </td>
            <td>
                <asp:TextBox ID="ddlSubject" runat="server"></asp:TextBox>
            </td>
        </tr>

        <!-- Message -->
        <tr>
            <td align="center">
                Message:
            </td>
            <td>
                <asp:TextBox ID="txtMessage" 
                                runat="server"
                                Columns="40"
                                Rows="6" 
                                TextMode="MultiLine"></asp:TextBox>
            </td>
        </tr>

        <!-- Submit -->
        <tr align="center">
            <td colspan="2">
                <a href="#btnSubmit">
                <asp:Button ID="btnSubmit" runat="server" Text="Submit" 
                    onclick="btnSubmit_Click" /></a>

            </td>
        </tr>

        <!-- Results -->
        <tr align="center">
            <td colspan="2">
                <asp:Label ID="lblResult" runat="server"></asp:Label>
            </td>
        </tr>
    </table>
</div>
</form>`

Answer 1

使用UpdatePanel，或者如果您真的要执行SPA，请考虑使用AJAX进行站点开发，并只编写Web服务。

Answer 2

Set this in your Page_Load function:

Page.MaintainScrollPositionOnPostBack = true; 

If you wish to return to the same scroll location on the page after the button is clicked.

Answer 3

You need to add MaintainScrollPositionOnPostback="true" to the "<%@ Page" tag, you can also set it in code-behind or web.config:

http://blogs.msdn.com/b/webdevelopertips/archive/2009/06/08/tip-75-did-you-know-how-to-maintain-scrollposition-after-post-back.aspx