Easiest way to create an auto incrementing column?

INSERT INTO SALES (PO_NUMBER) VALUES (GEN_ID(generator_name, 1));

/* This stored procedure returns a generated integer */
CREATE PROCEDURE GEN_BATCH_ID returns (ID_VALUE Integer)
AS
BEGIN
  ID_VALUE = gen_id(BATCH_ID_GEN, 1);
  SUSPEND;
END

/* Send this procedure an Employee's name. Get back the Employee's ID number. */
CREATE PROCEDURE EMPLOYEE_INSERT (LAST_NAME VARCHAR(25), FIRST_NAME VARCHAR(25)) returns (EMPLOYEE_ID Integer)
AS
BEGIN
  EMPLOYEE_ID = GEN_ID(EMPLOYEE_ID_GEN, 1);

  INSERT INTO EMPLOYEE (
    EMPLOYEE_ID,
    LAST_NAME,
    FIRST_NAME)
  VALUES (
    :EMPLOYEE_ID,
    :LAST_NAME,
    :FIRST_NAME);
END

Original - sql Code CREATE TABLE new_one ( col1 integer not null, col2 char(10), PRIMARY KEY (field1) );

CREATE TABLE new_one
(
col1 integer NOT NULL,
col2 CHAR(10),
PRIMARY KEY (field1)
); 

Original - sql Code CREATE GENERATOR my_gen_id;

CREATE GENERATOR my_gen_id; 

Original - sql Code CREATE TRIGGER autoincrementor_id FOR new_one ACTIVE BEFORE INSERT POSITION 0 AS BEGIN IF (NEW.col1 IS NULL) THEN NEW.col1 = GEN_ID(my_gen_id,1); END

CREATE TRIGGER autoincrementor_id FOR new_one
ACTIVE BEFORE INSERT POSITION 0
AS
BEGIN
IF (NEW.col1 IS NULL) THEN
NEW.col1 = GEN_ID(my_gen_id,1);
END