字符串比较的题目 - 编程论坛

字符串密码比较。若匹配则显示“MATCH”,否则显示“NOMATCH!,PROGRAM TERMINATED!”
我的代码

程序代码：

;预留字符串口令,输入口令串与预留密码串比较。若匹配则显示“MATCH”,否则显示“NOMATCH!,PROGRAM TERMINATED!”
DATAS SEGMENT
str1 db '1$'
str2 db 'please input a string:','$'
len equ $-str1
str_d db 50,?,50 dup(?)
mess1 db 0ah,0dh,'MATCH$'
mess2 db 0ah,0dh,'NOMATCH!,PROGRAM TERMINATED!$'
DATAS ENDS
CODES SEGMENT
    ASSUME CS:CODES,DS:DATAS
START:
    MOV AX,DATAS
    MOV DS,AX
    push ax
    mov dx,offset str2
    mov ah,09h
    int 21h
    pop ax
    mov es,ax
    lea dx,str1
    mov ah,0ah
    int 21h
    xor cx,cx
    mov cl,str_d
    cmp cx,len
    jne ms
    lea si,str1
    lea di,str_d
mad:mov al,ds:[si]
    mov bl,es:[di]
    cmp al,bl
    jne ms
    inc si
    inc di
    loop mad
    lea dx,mess1
    mov ah,09h
    int 21h
    jmp  exit

ms:
    lea dx,mess2
    mov ah,09h
    int 21h
exit:    MOV AH,4CH
    INT 21H
CODES ENDS
    END START

但就算我输入正确的字符串也得不到预期结果