比较两个字符，相等输出yes，不相等输出no

DATA SEGMENT
SHOW1 DB 'YES$'
SHOW2 DB 'NO$'
DATA ENDS
CODE SEGMENT
ASSUME CS:CODE,DS:DATA
BEGIN: MOV AX,DATA
MOV DS,AX
XOR AX,AX
MOV AH,1
INT 21H
MOV BL,AL
MOV AH,1
INT 21H
CMP BL,AL
JNZ NEXT
MOV DX,OFFSET SHOW1
JMP NEXT1
NEXT: MOV DX,OFFSET SHOW2
NEXT1: MOV AH,9
INT 21H
MOV AH,4CH
INT 21H
CODE ENDS
END BEGIN