Hello world in asm

HelloWord.asm

; Author: Juan Escobar
; /usr/include/i386-linux-gnu/asm/unistd_32.h
; nasm -f elf -o HelloWorld.o HelloWorld.asm
; ld -o HelloWorld HelloWorld.asm

global _start

section .text

_start:

        ; print "Hello World!" on the screen
        mov eax, 0x4     ; system call _write(fd, *buf, lenght)
        mov ebx, 0x1     ; file descriptor (standart output)
        mov ecx, message ; *buf
        mov edx, 0x0c    ; lenght (12) 
        int 0x80         ; interruptor

        ; exit the program
        mov eax, 0x1 ; system call _exit(status)
        mov ebx, 0x5 ; status (5)
        int 0x80     ; interruptor

section .data
        ; label
        message: db "Hello World!" ; define byte