A Simple Assembly Input Question

BITS 32
global _main
section .data

prompt db "Enter a string: ", 13, 10, '$'
input resd 1 ; something I can using to store the users input.

name db "Name: ******", 13, 10,'$'
StudentID db "********", 13, 10, '$'
InBoxID db "*************", 13, 10, '$'
Assignment db "************", 13, 10, '$'
version db "***************", 13, 10, '$'

section .text
_main:

mov ah, 9
mov edx, prompt
int 21h
mov ah, 08h
while:
	int 21h
            ; some code that should store the input.
	mov [input], al
	cmp al, 13
	jz endwhile
	jmp while
endwhile:

mov ah, 9
    ; displaying the input.

mov edx, name
int 21h
mov edx, StudentID
int 21h
mov edx, InBoxID
int 21h
mov edx, Assignment
int 21h
mov edx, version
int 21h
ret

; For each string already padded with 13, 10, $
; at the end, use the following:
mov ah, 08h
mov edi, string
mov ecx, max_chars
cld
while:
        int 21h
        stosb         ; store the character and increment edi
        cmp ecx, 1    ; have we exhausted the space?
        jz out
        dec ecx
        cmp al, 13
        jz terminate  ; pad the end
        jmp while
terminate:
        mov al, 10
        stosb
        mov al, '$'
        stosb
out:
        ; you can ret here if you wish