prepopulate textbox with variable, asp.net - asp.net

Question

I'd like to prepopulate my textfield with the following variable:
<%=Membership.GetUser().Email%>
... so that users can submit their email address to my table without having to type it in.
Here is my code:
<form id="form1" runat="server">
<div>
<!-- This is the code for the form. There is a Text Box to collect the first name,
last name and email address. All fields are required and I am validating that the
email address is a valid format. -->
<asp:Table ID="Table1" runat="server">
<asp:TableRow>
<asp:TableCell>First Name: <asp:TextBox ID="txtFirstName"
runat="server" Width="60" /> <asp:RequiredFieldValidator ID="RequiredFieldValidator1"
ErrorMessage="Enter First Name" Text="*" ControlToValidate="txtFirstName"
runat="server" />
</asp:TableCell>
<asp:TableCell>Last Name: <asp:TextBox ID="txtLastName" runat="server" Width="60" />
<asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server"
ControlToValidate="txtLastName" ErrorMessage="Enter Last Name" Text="*" />
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell>Email: <asp:TextBox ID="txtEmail" runat="server" Width="80" />
<asp:RequiredFieldValidator ID="emailRequired"
runat="server" ControlToValidate="txtEmail" ErrorMessage="Email Needs Information"
Text="*"/>
<asp:RegularExpressionValidator ID="emailexpression"
runat="server" ControlToValidate="txtEmail" ValidationExpression=".*#.*\..*"
ErrorMessage="Invalide Email Address" Text="*" />
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell>
<asp:ValidationSummary ID="ValidationSummary1" runat="server" ShowSummary="true"
ShowMessageBox="true" runat="server" />
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><asp:Button ID="btnSubmit" runat="server" OnClick="addMember"
CausesValidation="true" Height="30" Width="100" Text="Add Me" />
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell>
<asp:Label ID="lblDuplicate" runat="server" Text=""></asp:Label>
</asp:TableCell>
</asp:TableRow>
</asp:Table>
</div>
</form>
How can I accomplish this?

Answer 1

Pop it in the page load event in the code-behind?
if (!Page.IsPostBack)
{
txtEmail.Text = Membership.GetUser().Email;
}