whats wrong with my code?
.model small
.stack
.data
buffer db 10,?, 10 dup(' ')
.code
main proc
mov dx, offset buffer
mov ah, 0ah
int 21h
xor bx,bx
mov bl, buffer[1]
mov buffer[bx+2], '$'
mov dx, offset buffer + 2
mov ah,09
int 21h
ret
mov ah,4ch
int 21h
main endp
end main