Hi again,
Yes, now I see your intentions a bit clearer. Sorry for misunderstanding.
If you want to do partial refresh on your page, you have to use AJAX.
In Visual Studio 2010 you should perform following steps to do that:
1. Place ScriptManager from the AJAXExtensions tab in toolbox on your page
2. Place UpdatePanel on the page
3. Place gridview that needs to be refreshed in the UpdatePanel1 control
4. Button that causes the refresh (and populates gridview with data) should have it's UseSubmitBehaviour property set to "false" and should also be placed on that UpdatePanel (or another UpdatePanel but then you have to additionally after adding code for populating the gridview add UpdatePanel1.Refresh() method).
5. Set the UpdateMode property of UpdatePanel1 to "conditional"
I think that's it. All should work as you expect.