public down
extrn user:byte
code2 segment
down proc far	;大寫改爲(wèi)小寫

	xor dx,dx
	mov si,offset user
	add si,2

l4:	cmp byte ptr[si],'$'
	je l7
	cmp byte ptr[si],'Z'
	jbe l5
	inc si
	jmp l4
l5:
	cmp byte ptr[si],'A'
	jnl l6
	inc si
	jmp l4
l6:
	add byte ptr[si],20h
	inc si
	jmp l4
l7:
	ret
down endp
code2 ends
end