Ok, is seems like I knew how to do this, but for some reason, I'm just not making the right connections this morning. :) I have this union:

SELECT purno, potype, purdate, currid, postat, puramt, recamt, vendno, company, "C" AS chfile ;
  FROM a_pomast ;
  INTO CURSOR ac_pomast ;
UNION ;
SELECT purno, potype, purdate, currid, postat, puramt, recamt, vendno, company, "H" AS chfile ;
  FROM a_poymst

There are some records that are in both tables. Normally, they would be filtered out as duplicates. But because I added that extra field to tell me which table they came from, they're showing up as unique. How do I tell it to filter duplicates based just on the purno?

Thanks,

Michelle