[AccessD] Combine two tables

Hi, everybody,

In an Access 2002  I have two linked tables,
table A is in the BE which belongs to this FE,
table B is in a different database, and it is used there as well.
Both tables are lists of persons with id, lastname, firstname, and other 
fields.

I want to use names from both tables as customers.
I have made a union query, but this gives me duplicate id numbers.

Is there a way to insert the source table name into the union query,
so that I can then distinguish from which table a certain record is?

Or is there a better solution?

Thank you
Lembit