It has been a long while since I used ASP Grid Views for editing.
Open your aspx page that you are talking about in Visual Studio.
Select Split, or Design view of this page.
Navigate down to where your GridView is.
there should be a > in a button, if you click this you can see "Configure Data Source" as one of the options.
In here you can set what you want it to do on SELECT, UPDATE, INSERT, DELETE.
See the following link
http://www.asp.net/data-access/tutorials/using-templatefields-in-the-gridview-control-cs[
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This link here can help you in another way.
Editable GridView in ASP.NET 2.0[
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Good luck