Duplicating GridView's Edit Functionality

When a GridView performs a row edit, edit controls appear without needing to
display a different page, or, apparently, needing to refresh the existing
page.

Does anyone have tips on duplicating this functionality. I'm guessing it
involves a bunch of javascript, which my abilities are limited with.

I need to edit some data that will exist in an array and not directly in a
database. I know I can use an array as the GridView's datasource, but then
how would I update it?

Thanks.

Jonathan