event when leaving a record without update

[SMoeller]

In data entry view of my form, I would like to post a msgbox if the user
leaves a record and a specific field has no value. What is the event that
triggers this. Before/After Update does not work since I also need this even
if no update is made in a record (the user has only looked at a record). I
tried event unload too, does not work.
Thanks in advance!

 

[BruceM via AccessMonster.com]

I can't imagine why you would want to pester people with a message rather
than requiring a value in the first place, but I suppose you could make your
own navigation buttons instead of the built-in ones, and test the field's
value as the first thing in the command button code.