Well, it's an easy job just follow these addresses that will help you so much:
http://www.asp.net/learn/data-access/tutorial-19-cs.aspx
http://www.asp.net/learn/data-access/tutorial-13-cs.aspx
http://www.asp.net/learn/data-access/tutorial-12-cs.aspx
http://www.asp.net/learn/data-access/tutorial-17-cs.aspx
An additional comment: don't forget to convert the Edit, Cancel, Update button into a TemplateField too!
