ACCEPT ENUM PROMPT 'ENTER THE EMPLOYEE NUMBER:  '
DECLARE
	SALARY	EMP.SAL%TYPE;
	COMS	EMP.COMM%TYPE;
BEGIN
	SELECT SAL
	INTO SALARY
	FROM EMP
	WHERE EMPNO = &ENUM;

	IF SALARY <  1000  THEN
		COMS :=  0 . 1 ;
	ELSIF SALARY <=  1500  THEN
		COMS :=  0 . 15 ;
	ELSIF SALARY >  1500  THEN
		COMS :=  0 . 20 ;
	ELSIF SALARY IS NULL THEN
		COMS :=  0 . 0 ;
	ENDIF;

	UPDATE EMP
	SET COMM = NVL(SALARY,  0 ) * COMS
	WHERE EMPNO = &ENUM;
END;
COMMIT;
/