[C++] Problema con applicazione Win32

[Sart]

Ah già scusami l'avevo tolta

comunque l'avevo inserita all'inizio:

#include "stdafx.h"
#include "GL files creator.h"
#include <windows.h>
#include <iostream>
#include <string.h>
#include <gl/gl.h>
#include <gl/glu.h>
#include <gl/glaux.h>

#pragma comment(lib, "OpenGL32.lib")
#pragma comment(lib, "GLu32.lib")
#pragma comment(lib, "GLaux.lib")

#include "loader.cpp"

#pragma comment( lib, "comctl32.lib")
#include <commctrl.h>
#pragma comment(linker, "/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' \processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")

HWND toolbar=NULL, listbox=NULL, edit=NULL, button=NULL, label=NULL;
HINSTANCE hInstanceM;

int length, init;

int type=NULL;

OPENFILENAME prova;

BOOL CALLBACK AboutDlgProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam){
	switch(Message){
		case WM_INITDIALOG:
    ........