Verify GridView Edit

[David]

I have a GridView with an Edit command. I am setting a flag when the edit
starts and turning it off when the row is updated. I want to give the user
a warning (I am using onbeforeunload javascript function in body) if they
select Edit but do not Cancel or Update. However, when the Cancel button is
clicked, the page leaves and the warning pops up. How can I bypass the
warning in this situation? Thanks.

p.s. I use this same process on a FormView and it works great, but not on a
GridView.

David