SQL Help Needed

Now, the data from tblBenchmark, benchmarkID and Benchmark should only be linked to a contactID (via tblContactBenchMarkLink) ONCE.

What I want to do is use some code, perhaps via the form_current event, to requery the combo box to NOT include benchmarks that already have a record in tblContactBenchMarkLink for the current contact.

For example, if there are:
4 benchmarks - power (BenchMarkID=1), top_speed (2), standard_equipment (3) and fuel_economy (4)
2 contacts - Bob (ContactID=1) & Sam (2)

and tblContactBenchMarkLink contains two records -
ID 1, ContactID 2, BenchmarkID 2
ID2, ContactID 2, BenchmarkID 3

The next time I select Sam's record, and click on the combo box that allows me to select his benchmarks in a new record in tblContactBenchMarkLink, I want only power and fuel_economy to appear, since I've already told the db that Sam cares about top_speed and standard_equipment.

Does anyone know if this is possible, and if so, how to go about it? I think it's probably just a case of updating the recordsource property of the combo when the form's current, but I'm not sure how to write this sql string.

• Here's the thing I need to do then - select BenchMarkID and Benchmark fields from tblBenchmark when the records corresponding to a particular contact in tblContactBenchmarkLink do NOT contain the BenchmarkID

Here's hoping someone knows of a solution!

Thx in advance,

Aljrob