From: GA on
I've thought myself into a corner and am probably missing something
blindingly obvious so I'd appreciate being pointed in the right

I have an Access database that has linked tables to 2 SQL servers.
The main back end, I have full control of but the second one provides
read only access to the full contact details of about 500 contacts.

My main form is based on a set of publications that are for sale. I
have a set of sub-forms on a tab control one of which is the record of
sales for each publication.

Out of the contacts, there are about 20 non-subscribers and as I
cannot write to the contacts datanase, I have created a separate table
with just an ID and Name field using a combobox based on the read only

When a new sale record is completed, the customer field is a combo
based on the read only contacts table, but it can also accept entries
which are not in the the list. I've put a large red label on the sales
sub-form to warn when a customer is a non-subscriber and to do this I
need to determine one of three possibilities -

1. The customer exists in the read only contacts table and is not in
the non-subscribers table.
2. Diitto but is in the non-subscribers table
3. It's a customer who isn't in the contacts table.

In the second and third cases I want to display the label (which is
set not visible by default) and in the first I want to keep it hidden.

I started by trying to use DLookup to compare to "Me.Customer" in the
"after update" of the customer control but just got completely

Can anybody help please or point me to a working example of this sort
of problem.

Thanks in advance,