prnstr macro msg
    mov ah, 09h
    lea dx, msg
    int 21h
    endm

data segment
    bufo1 db "Enter a string : $"
    bufi db 11
         db 0
         db 11 dup(' ')
    bufo2 db 0ah, "You entered : $"
data ends

code segment
    assume cs:code, ds:data
start :
    mov ax, data
    mov ds, ax

    prnstr bufo1

    mov ah, 0ah
    lea dx, bufi
    int 21h

    mov si, offset bufi + 1
    mov cx, 0000h
    mov cl, byte ptr [si]
    add si, cx
    mov byte ptr [si+1], '$'

    prnstr bufo2
    prnstr bufi+2

    mov ax, 4c00h
    int 21h
code ends
    end start