Newbie

[Paco Quintana]

Hi all
I am new in wxwidgets and need an answer about a beginner question.
In creating a new project (frame) if its necessary to work for example 
with fstream I need to #include <fstream> Where do i write my include 
statement ( in wich file of the project) or if I need to include my own 
customer class where is the correct place to write my #include "customer.h"
Thanks in advance.
Paco