你好，如果任何人可以帮助我与此代码，我面临的问题，我不知道确切的错误是什么，但它只与前几步工作，然后当它coms让用户输入一个消息，它导致错误

; multi-segment executable file template.

data segment
    ; add your data here!
    pkey db "press any key...$" 
    prompt1 db "if u want to encrypt,type E,if u want to decrypt,type D:",0Ah,0Dh,"$"
    prompt2 db "enter the encryption key(a single digit from 1 to 9):",0Ah,0Dh,"$"
    prompt3 db "input a message of no more than 20 characters ,when done press <ENTER>:",0Ah,0Dh,"$"
    message db 20 dup(?)
    result db 20 dup(?)
ends

stack segment
    dw   128  dup(0)
ends

code segment
start:
; set segment registers:
    mov ax, data
    mov ds, ax
    mov es, ax
                               
                             
    ; add your code here  
    ; prompt the user for input
    mov ah, 09h
    mov dx, offset prompt1
    int 21h        
    ; read the user's input and store it in x3100
    mov ah, 01h
    int 21h
    mov [3100H], al  
    ; prompt the user for the encryption key
   mov ah, 09h
   mov dx, offset prompt2
   int 21h  
   ; read the encryption key and store it in x3101
mov ah, 01h
int 21h
mov [3101H], al

; prompt the user for the message
mov ah, 09h
mov dx, offset prompt3
int 21h

; read the message and store it in x3102
mov ah, 0ah
mov dx, offset message
int 21h

; encrypt/decrypt the message based on the user's input
mov al, [3100H]
cmp al, 'E'
je encrypt
cmp al, 'D'
je decrypt
; encrypt the message
encrypt:
    mov si, offset message
    mov di, offset result
    mov bx, [3101H] ; encryption key
    mov cx, 20 ; number of characters to process

encrypt_loop:
    ; toggle the low-order bit of the ASCII code
    mov al, [si]
    xor al, 1
    add al, [bx] ; add the encryption key
    mov [di], al
    inc si
    inc di
    loop encrypt_loop

; output the encrypted message
mov ah, 09h
mov dx, offset result
int 21h
; decrypt the message
decrypt:
    mov si, offset message
    mov di, offset result
    mov bx, [3101H] ; encryption key
    mov cx, 20 ; number of characters to process

decrypt_loop:
    ; subtract the encryption key from the ASCII code
    mov al, [si]
    sub al,[ bx]
    ; toggle the low-order bit of the result
    xor al, 1
    mov [di], al
    inc si
    inc di
    loop decrypt_loop

; output the decrypted message
mov ah, 09h
mov dx, offset result
int 21h

                      
                      
            
    lea dx, pkey
    mov ah, 9
    int 21h        ; output string at ds:dx
    
    ; wait for any key....    
    mov ah, 1
    int 21h
    
    mov ax, 4c00h ; exit to operating system.
    int 21h    
ends

end start ; set entry point and stop the assembler.

它告诉我纠正int 21/9 h的示例

mov dx,offset message 
mov ah,9

我甚至不知道错误在哪里