Querying data

Yikes...today is my last day on this job and I'm trying to wrap up dozens of
things...so please forgive me for not exhausting other resources before
throwing this question out to you all...somehow I think this should be
easy....but my brain is crowded with other diversions at this moment...

Here is the question I am asking Access ...Upon entry of a zipcode....please
show me the vendor for Class 1, Class 2, Class 3 and Class 4.

I have zipcodes and counties and vendor numbers in one table. I another
table in which I have primary contact info for each vendor. I have four
classifications of service that can go with each vendor and I indicate those
classes by a yes/no check box in the same table as my vendors. Each vendor
can have checked from one to four differerent classifications. The link is
the vendor number in the zipcode table and the vendor table. So every zip
code could have any combination of vendor info....the same vendor for all
classes or a different vendor for each class. But, never more than one
vendor per class.

Anyway we can make this fast and easy.....thanks ever so much! !!!