sql problem with php

Hi,

I am having a problem with a system I developed using php with postgres.

Take a look at this:
Welcome to psql 7.3.2, the PostgreSQL interactive terminal.
NetAdmin=# delete from operador where oplogin = 'ff';
ERROR: fk_historicosessao_operador referential integrity violation - key in
operador still referenced from historicosessao

and then, this:

Welcome to psql 7.4.2, the PostgreSQL interactive terminal.
NetAdmin=# delete from operador where oplogin = 'ff';
ERROR: update or delete on "operador" violates foreign key constraint
"fk_historicosessao_operador" on "historicosessao"

I am not able to get a error_number in pgsql errors, only the error message.
So when I used pgsql 7.3 a used the string "referential integrity violation"
to detect this error, but on version 7.4 of pgsql this string was replaced
with "violates foreign key constraint" .
Anyone has a definitive solution on this or the way is to wait and change all
my code on future releases of pgsql?

Thank you all for the attention.
--
Att.

Flavio Fonseca
Administrador de Redes
Divisao de Redes
Universidade Federal de Uberlandia