Merge & Purge Question

[Rangoon]

I have two lists both on FileMaker Pro 5.5. File 1: has 5,000 names (with Name and Address in the [CONTACTS]file and Phone Numbers in the [PHONE]file related by unique ID Nbr..

File 2: has 15,000 names (with Name and Address in the [CONTACTS 2]file and Phone Numbers in the [PHONE 2]file related by unique ID Nbr..

What I need to do is run the list of 5,000 "current customers" agains the 15,000 "customers & prospects", eleminating duplication by "PHONE NUMBER". Then I need to keep my list of 5,000 customers and add what is left of the 15,000 names after the Purge. What's the best way to do it?

Thanks for your help, Harry