year_limit_left number := 50;
    year_limit_right number := 3;
    procedure CHK_HIREDATE(v_date IN DATE)
    IS
    limit_left DATE;
    limit_right DATE;
    e_exc EXCEPTION;
    PRAGMA EXCEPTION_INIT (e_exc , -20007 );
    BEGIN
    limit_left := ADD_MONTHS(SYSDATE, -(12 * year_limit_left));
    limit_right := ADD_MONTHS(SYSDATE, (12 * year_limit_right));
    IF v_date > limit_right OR v_date < limit_left THEN
        RAISE e_exc;
    END IF;
    EXCEPTION
            WHEN e_exc THEN
                RAISE_APPLICATION_ERROR ( -20007 , 'Invalid hiredate.' );
    END CHK_HIREDATE;