validation issue

[robert oneill via AccessMonster.com]

Hi there, I'm doing a Access database for a college asignment and i'm stuck
on problem with a booking form.
Is there a way of when a membership number is added into the booking tabel
that it checks the membership number exists in the membership table. If it
does not exist i need a message to pop up to give the option to add the
membership.
Robbie

 

[Pat Hartman]

If you use a combobox with its limit to list property set to yes, you won't
need any code at all. If you like code, you can use a DLookup() in the
BeforeUpdate event of the MembershipID field. If the ID is not found,
cancel the event. In either event, make sure that the relationship is
properly defined and the option to enforce RI is selected.