Presumably you have a *reason* for wanting the hobble the user in this way.
(I have a personal dislike for software that forces users to work in one
particular way: it generally indicates that the developer did not understand
how to handle events properly.)
In any case, if you are using a command button to close forms, you need to
know that there is a serious data-loss bug in Access, where it just silently
throws away the user's entry without any warning if there is a problem with
the entry (e.g. a required field missing, validation rule not met, duplicate
index issue, etc.)
This is a major problem in Access, leading people to mistrust the software.
They know they entered something, but later it's not there. I can't believe
we can't get this fixed after 12 years in Access. More info:
http://allenbrowne.com/bug-01.html