How to get last Error Message/Code

Hi,

I am new to Postgres and I would like to know how I can get the last error message.
I am using a programming language called "Paradox" and, when an error occurs,
it converts the Postgres error code to its own error code.
Sometimes Paradox displays a funny message, if it does not recognize the code and
the error message it displays gives me no clue for what actually happened.

if anyone knows the solution, please let me know.

Thank you in advance.
Cheers!