Shestakov--

thanks... it still didn't work.
i started getting:

Warning: Trigger created with compilation errors.

Errors for TRIGGER BANINST2.TT_TZGTEST_INSERT_PIDM:

LINE/COL ERROR
-------- --------------------------------------------------------------
19/13 PLS-00103: Encountered the symbol "NULL" when expecting one of the following:
in like between
The symbol "like" was substituted for "NULL" tocontinue.

so i changed "if pidm not null then" to "if pidm > 0 then"
and started getting this error:

CREATE OR REPLACE TRIGGER baninst2.tt_tzgtest_insert_pidm
*
ERROR at line 1:
ORA-00600: internal error code, arguments: [16221], [], [], [], [], [], [], []

No errors.

It might be time to go a different route, but surely this can be done.