[Source]#include <windows.h>#include <tchar.h>#include <time.h>#include <stdio.h>#include <stdlib.h>// Windows application variables.HWND				g_hWnd				 = 0;			  HINSTANCE			g_hInstance			 = 0;		  BOOL				g_bActive			 = FALSE;	BOOL				g_bDone				 = FALSE;TCHAR				g_szAppClass[]		 = TEXT( "Application" );TCHAR				g_szAppTitle[]		 = TEXT( "Connect Four" );// Windows application function prototypes.LRESULT	WINAPI MsgProc( HWND, UINT, WPARAM, LPARAM );// Game application function prototypes.void initGame();void mainGame();void shutdownGame();//---------------------------------------------------------------// Name: WinMain()// Desc: Called as soon as the Application is loaded.//---------------------------------------------------------------int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance,				    LPSTR lpCmdLine, int nCmdShow ){	WNDCLASSEX	wndclass;	HWND		hWnd;	MSG			msg;	// Setup the window attributes	wndclass.cbSize			=	sizeof( wndclass );	wndclass.style			=	CS_HREDRAW | CS_VREDRAW | CS_OWNDC | CS_DBLCLKS;	wndclass.lpfnWndProc	=	MsgProc;	wndclass.cbClsExtra		=	0;	wndclass.cbWndExtra		=	0;	wndclass.hInstance		=	hInstance;	wndclass.hIcon			=	LoadIcon( NULL, IDI_APPLICATION );	wndclass.hCursor		=	LoadCursor( NULL, IDC_ARROW );	wndclass.hbrBackground	=	( HBRUSH ) ( COLOR_WINDOW );	wndclass.lpszMenuName	=	NULL;	wndclass.lpszClassName	=	g_szAppClass; // Registered class name	wndclass.hIconSm		=	LoadIcon( NULL, IDI_APPLICATION );	// Register the new window	if( RegisterClassEx( &wndclass ) == 0 )		exit(1);	// Create the main window.  Window parameters make the main window	// 640X480 only	hWnd = CreateWindow( g_szAppClass,			// Class Name						 g_szAppTitle,			// Name displayed on title bar						 WS_OVERLAPPEDWINDOW,	// Window style, using Popup						 0,						// X Position (Top Left)						 0,						// Y Position (Top Right)						 640,					// X Position (Bottom Right)						 640,					// Y Position (Bottom Left)						 NULL,						 NULL,						 hInstance,						 NULL );	// Tell windows to show the application	ShowWindow( hWnd, nCmdShow );	// Update the client by sending an initial WM_PAINT msg	UpdateWindow( hWnd );	// Save the main window handle	g_hWnd = hWnd;	// Save the main application instance	g_hInstance	= hInstance;	initGame();   // Main Message Loop.  Keep looping through this application until	// the user chooses to exit.  When the user chooses exit by clicking	// the red X box top right of the window for example.  A WM_QUIT	// message will be sent to the application which prompts the application	// to exit.   ZeroMemory( &msg, sizeof( msg ) );   while( !g_bDone )    {		while( PeekMessage( &msg, NULL, 0U, 0U, PM_REMOVE ) )		{			TranslateMessage( &msg );			DispatchMessage( &msg );		}		if(msg.message == WM_QUIT)		{			break;		}		if( g_bActive )		{			mainGame();		}   }   shutdownGame();			   UnregisterClass( g_szAppClass, hInstance );   // Return back to Windows   return( ( int ) msg.wParam );}//---------------------------------------------------------------// Name: MsgProc()// Desc: This is the main window message handling function//---------------------------------------------------------------LRESULT WINAPI MsgProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam ){	PAINTSTRUCT ps;	HDC			hdc;	switch( msg )	{	case WM_PAINT:		hdc = BeginPaint(hWnd, &ps);		EndPaint(hWnd, &ps);	break;	case WM_ACTIVATE:		// The message WM_ACTIVE is sent whenever the application has focus.		// For example if the application is minimised then it is not in focus.		// As the application is not in focus it is pointless wasting clock		// cycles and graphics hardware to render to what cannot be seen.		g_bActive = ( BOOL ) wParam;	break;	case WM_KEYDOWN:		// Whenever a key is pressed (non-accelerated ie shift and f5, then		// this message is sent.		switch( wParam )		{		case VK_ESCAPE:			// If the user presses the Escape key then we will quit the 			// application			g_bDone = TRUE;			PostMessage( g_hWnd, WM_CLOSE, 0, 0 );			return 0;		};	break;	case WM_DESTROY:		// The message WM_DESTROY is sent by the Windows Messaging System		// when our message queue recieves the WM_QUIT message from the		// application.  It just cleans everything up and quits the 		// application		g_bDone = TRUE;		PostQuitMessage( 0 );		return 1;	break;	default: break;	}		// If any messages reach here then it was not handled by our application.	// So we will return it back to the queue so the next Windows application	// like a background task.	return DefWindowProc( hWnd, msg, wParam, lParam );}//---------------------------------------------------------------// Name: initGame()// Desc: //---------------------------------------------------------------void initGame(){	// Initialisation.}//---------------------------------------------------------------// Name: mainGame()// Desc: //---------------------------------------------------------------void mainGame(){	// Game calls.}//---------------------------------------------------------------// Name: shutdownGame()// Desc: //---------------------------------------------------------------void shutdownGame(){	// Cleanup.}[/Source]