PL/SQL

What does the following code do ? Replace the error messages "error1" and "error2" with more meaningful messages. CREATE OR REPLACE PROCEDURE add_new_supplier (supplier_id_in IN NUMBER, supplier_name_in IN VARCHAR2) Is BEGIN INSERT INTO suppliers (supplier_id, supplier_name ) VALUES ( supplier_id_in, supplier_name_in ); EXCEPTION WHEN DUP_VAL_ON_INDEX THEN raise_application_error (-20001, 'error 1.'); WHEN OTHERS THEN raise_application_error (-20002, 'error 2.' ); END