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!