I am doing Narue's Introduction to Assembly, and when I run my program, nothing happens.

This is my code:

[section .data]
	hello: db 'Hello, world!', 10, 0

[section .text]
	global _main
	extern _printf
_main:
	push  hello
	call  _printf
	add   esp, 4
	mov   eax, 0
	ret

This is what happened in my command window:

C:\Documents and Settings\tom\Desktop\Assembly>nasm -f win32 First.asm -o First.obj
C:\Documents and Settings\tom\Desktop\Assembly>gcc First.obj -o prog.exe
C:\Documents and Settings\tom\Desktop\Assembly>prog.exe
C:\Documents and Settings\tom\Desktop\Assembly>

Any help would be appreciated :)