CREATE OR REPLACE PACKAGE table_ids AS
   TYPE return_cursor IS REF CURSOR;
   PROCEDURE get_next_session_id(session_cursor OUT return_cursor); 
END table_ids;
/
CREATE OR REPLACE PACKAGE BODY table_ids AS 
PROCEDURE get_next_session_id(session_cursor OUT return_cursor) IS
   BEGIN
      OPEN session_cursor FOR
      SELECT
             'S'||lpad(session_id.nextval,5,'0')
      FROM dual;
      EXCEPTION
         WHEN NO_DATA_FOUND
              THEN raise_application_error(-20000, 'No more rows.');
         WHEN OTHERS
              THEN raise_application_error(-20001, 'There was an undeterminable error.');
END get_next_session_id;