Hi, here is the code below:
Note:
1. be sure to add ScriptManager inside form tag.
2. whatever content you want to update put inside <updatepanel><contenttemplate>
3. buttons used inside this updatepanel will cause automatic postback
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<div>
<table class="style1">
<tr>
<td class="style2">
Enter Your Email</td>
<td>
<asp:textbox id="txtEmail_1" runat="server" style="margin-left: 0px" xmlns:asp="#unknown">
Width="526px"></asp:textbox>
</td>
</tr>
<tr>
<td class="style2">
<asp:textbox id="txtpass" runat="server" xmlns:asp="#unknown"></asp:textbox></td>
<td>
<asp:button id="Button1" runat="server" text="Button" xmlns:asp="#unknown" />
</td>
</tr>
<tr>
<td class="style2">
<asp:button id="Button2" runat="server" text="Cancel" xmlns:asp="#unknown" /></td>
<td>
</td>
</tr>
<tr>
<td class="style2">
</td>
<td>
</td>
</tr>
</table>
</div>
</ContentTemplate>
</asp:UpdatePanel>