Is there a way to combine SEEK with SELECT (or a better way) to select records EXCEPT for those referenced in another table?

I have two tables:

The main table contains all records indexed by an ID field.

The second table contains the IDs of records from the first table that have already been processed, also indexed by the ID field.

I wish to select all records from the first table EXCEPT those for which the ID is listed in the second table.

It would seem that a statement such as this should work:

SELECT  (fieldnames);
 FROM  main_table;
 WHERE (search criteria);
   AND NOT SEEK(done_table.id);
   into cursor c_results

I'm obviously overlooking something....

All assistance appreciated!

Thanks,

Neil Preston