Help setting up autolookup query and form

[lss]

I've browsed the forums and even checked out Northwinds database. Both seem to include pieces but I don't quite know how to set up what I need.

We input new customers in a customers table. It includes the basic info, name, address, city, state, and zip, among other fields. We split up groups of zip codes into areas A and B for ease in conducting business. Thus, we created a new table which includes the zip code and corresponding A or B.

When inputting new customer info, I thought it would be easier if we could input the street address, but look up either the city or zip code and have the city, state, zip and area automatically complete for each customer record, including that info with the customer's data.

As I try to apply this to other people's projects, I'm getting confused as to what ID fields need to tie together, how many tables and queries I need, and is it as simple as choosing something in a form to update the customer table?

I'm making an assumption that I would have one zip code entry to many customer entries. However, I would not need to see all the customers in any one zip code for any reason. This is different than having an employee related to several training issues, for example, or a customer to several orders.

 

[lameid]

You need a table that relates cities to zip codes. Problem is that each zip code often has many valid names. Sometimes the township name is just as valid as the city name. The USPS site has the prefered city if multiple are valid. Another site I like is

http://www.getzips.com/zip.htm

It also tells you the county which is invaluable for taxes if you supply commodity through a utility (Gas, Electricity etc).