Can't add new record to popup

[Aaron G]

Using Acess 2003

I have two tables with a one-to-many relationship. I have the data (contact
info) for the first table displayed on a form. I want to be able to add
records to the second table via a popup that will relate the new record back
to the contact on the first table (and main form).

I created a command button that shows all the records, but as soon as I try
to add a new record, it loses the link to the first table.

What do I need to do to get this done?

TIA

Aaron G
Philadelphia, PA