How coul I compare 2 strings, one that is given by a use and the other one from data segment in memor, in assembler?
for exemple:

assume cs:code,ds:data

data segment
 parola db 'mananca$'
 introdu db 20,?, 20 dup (?)
 gresit db 'Mai incearca$'
 corect db 'Ai ghicit$'
 linieNoua db 10,13,'$'

data ends

code segment
 start:
 mov ax,data
 mov ds,ax
 mov ah,09h
 mov dx, offset parola
 int 21h
 repeta:
   mov ah,0Ah
   int 21h 
   mov al,parola
   cmp al,introdu ; here is sth wrong
   jne next
   mov ah,09h
   mov dx,offset linieNoua
   int 21h
   mov ah,09h
   mov dx,offset corect
   int 21h
   mov ax,4c00h
   int 21h
   next:
   mov ah,09h
   mov dx,offset linieNoua
   int 21h
   mov ah,09h
   mov dx,offset gresit
   int 21h
   mov ah,09h
   mov dx,offset linieNoua
   int 21h
   jmp repeta
code ends
end start

First, comment each line with what you are intending it to do. Next, I havent been doing serious x86 assembler programming in 20 years so I need your comments in order to understand your intentions.

Also, which compiler are you using? There are many flavors of assembly language...