How to edit datas in grigview.

Hi,
Function is editing in the gridview, when edit button is click it shows the row records in the popup box not in the same gridview.
for this i have used.

Here is the code..
<asp:BoundField DataField="username" HeaderText="Name"></asp:BoundField>

In .cs file
cmd.Parameters.AddWithValue("@username", txt_name.Text.Trim());

txt_name.Text = row.Cells[7].Text;

this works fine.. but when i convert the Bound field in to Template Field , its showing the datas in gridview. when i click edit button,
Ajax popup box opens but not displaying that text in that popup box from grid.

its not fetching datas from the grid to popup textbox.

<asp:TemplateField HeaderText="Customer">
<EditItemTemplate>
<asp:TextBox ID="txt_name" runat="server" Text='<%# Bind("Name") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="lblname" runat="server" Text='<%# Bind(Name") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>

SATHIYANARAYANAN