.MODEL	SMALL
	.STACK	100H
	.DATA
STAT	DB	0
	.CODE
	MOV	[STAT],08H
LUS:	MOV	AH,02H
	INT	16H
	AND	AL,0FH
	XOR	AL,[STAT]
	JNE	LUS
	SHR	[STAT],1
	JNE	LUS
	MOV	AH,4CH
	INT	21H
	END