I am trying to examine the values of $_TD->{new}. I thought the easiest way to see what this structure looked like was to use the Dumper functionality. To do so I need to include the appropriate Perl module, which I would think would be done like this: use Data::Dumper qw(Dumper); But inserting that into the script to create the function, like this: CREATE OR REPLACE FUNCTION valid_id() RETURNS trigger AS $$ use Data::Dumper qw(Dumper); if (($_TD->{new}{i} >= 100) || ($_TD->{new}{i} <= 0)) { ...... Returned this error message: ERROR: Unable to load Data/Dumper.pm into plperl at line 2. BEGIN failed--compilation aborted at line 2. CONTEXT: compilation of PL/Perl function "valid_id" What do I have to do to use Perl modules in plperl function/ BTW this works outside plperl #!/usr/bin/perl use strict; use warnings; use Data::Dumper qw(Dumper); .................. Thanks for the help. -- "They that would give up essential liberty for temporary safety deserve neither liberty nor safety." -- Benjamin Franklin