i saw this post on
http://connect.microsoft.com/VisualStudio/feedback/details/105131/controls-in-gridview-edititemtemplate-not-available-in-codebehind-or-datasources#details
so the problem is .... if there is a datasource in some editeitem template in grid view .... it won't be accessible from out of the edit-item field.....
here's my code...
<asp:GridView ID="GridView1" runat="server" DataSourceID="ObjectDataSource1" AllowPaging="True" AutoGenerateColumns="False" DataKeyNames="ID">
...
Go to the complete details ...