Access 2000 VB question

This is my code:
If Me![ClientNum] = DLookup(“ClientNum”, “ZParPay”) Then
Me![Highlight01].Visible = True
End If

The code is supposed to highlight a label
on a form to alert the user that a partial
payment was made on the account and to then
inquire to the client if they wish to make
another deposit or final payment on that
account.

The problem I am having is that the Dlookup
underlying query does not requery for each
record moved to.

Would appreciate some help to make DLookup
to requery for each client number. I know
it is not doing this as I made an unbound field
that is directly related to the DLookup and
that field remains the same for every client
after the first one meets that evaluation.

Thanks