帮忙看下哪里错了？
这段程序是为了实现 统计在 buf中字符 B的个数，0为结束DATAS SEGMENT
buf db 'Bjkdsa0'
DATAS ENDS
STACKS SEGMENT
;此处输入堆栈段代码
STACKS ENDS
CODES SEGMENT
ASSUME CS:CODES,DS:DATAS,SS:STACKS
START:
MOV AX,DATAS
MOV DS,AX
mov al,0
lea bx,buf
bijiao:
cmp buf[bx],'B'
je jia
cmp buf[bx],'0'
je ok
inc bx
jmp bijiao
jia: inc al
jmp bijiao
ok: add al,30h
mov dl,al
mov ah,2
int 21h
MOV AH,4CH
INT 21H
CODES ENDS
END START
