Can someone tell me how to add/edit a row in a Gridview

How do I use a common add & edit button for the gridview Also, how do I select a row in a gridview without explicitly using a commandfield or buttonfield I need to select the row, pass the column ID value & then click the edit button to perform the operation.

And, when I try using

updatePanel1.visible = false; //works

But when I try to make it visible: updatePanel1.visible = true; //it doesn't do anything, any idea why

I am working in .NET 2.0.

Any help will be very useful. Thanks.