help with a procedure

Hi everyone, I wonder if you could help me with a procedure that I would like to perform in postgresql.

I have an insert query like this:

INSERT INTO products (product_id, description, price, qty, ...) values ('01', 'some description', 10.15, 5, ...)

So the second query depends of the first query, if the first one succeed the second will perform the second insert

I would like to do something like:

SELECT myProcedure(product_id, p_description, price, qty, store_id, store_description );

waiting for a response from procedure, maybe true or false.

Thanks in advance...