postgre and sqlerror handling

Hello All

I am using postgresql in a 'C' program running on Linux. It's a simple program which inserts a row. This insert should give error. However in spite of me having error handling when I run this program it generates hundreds of the following error message:

"cannot insert duplicate key into a unique index
NOTICE: UserAbortTransactionBlock and not in in-progress state."

I do not know why it does not use err handler and stop after first error.

2) Also when I use goto err_handler in my code it gives compile error. Can ayone suggets the correct syntax.

Thanks All
Ravi