Win CE to Windows XP quitbutton

/* 2010-03-06 john pfeiffer windows (from win ce version) quit button
*/

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

/* define a special numeric ID for our buttons */

#define  IDC_ExitButton      40099
#define  IDC_clearScreen    40098

/* HDC = handle to device context - a logical buffer of the screen. 
You "write" things to it and then it can write to the display in a chunk.
A paint structure contains the info about the area being painted.

Direct from MSDN...
typedef struct tagPAINTSTRUCT {
  HDC  hdc;
  BOOL fErase;
  RECT rcPaint;
  BOOL fRestore;
  BOOL fIncUpdate;
  BYTE rgbReserved[32];
} PAINTSTRUCT, *PPAINTSTRUCT;

*/

VOID APIENTRY initializeBackground(  HWND hwnd )
{   HDC  hdc;
    PAINTSTRUCT ps;
    hdc = BeginPaint(hwnd, &ps);    /* prepares the window for painting */
    EndPaint(hwnd, &ps);            /* done painting */
}

/* This is the prototype to the "do everything" window message
processing switch function */

LRESULT CALLBACK MenuWndProc( 
HWND hwnd,   UINT message, WPARAM wParam,   LPARAM lParam);

int APIENTRY WinMain(
    HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    LPTSTR lpCmdLine, int ncmdshow )
{ 
    HWND hwnd = NULL;  
    HWND ExitButton = NULL;         /* each button gets a window handle */
    HWND clearScreenButton = NULL;

    MSG msg;   
    WNDCLASS wc;
    RECT rc;

    wc.style = CS_HREDRAW | CS_VREDRAW;         
    wc.lpfnWndProc = (WNDPROC)MenuWndProc; 
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = 0;
    wc.hCursor = 0;
    wc.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = (LPTSTR) "AppClass";

  if(!  RegisterClass (&wc))
{     MessageBox(NULL, TEXT("errors "),
  "IMPORTANT", MB_OK); 
    return 0;
 }

/* create our main window letting windows decide the placement & size 
NOTE! THE CLASS NAME MUST BE A LONG! - could use TCHAR?*/
    hwnd = CreateWindow ( "AppClass",

    "quit button app", WS_VISIBLE,
        CW_USEDEFAULT, CW_USEDEFAULT, 
        CW_USEDEFAULT, CW_USEDEFAULT,        
        (HWND)NULL, NULL, hInstance, (LPSTR)NULL);

/* ----------- ----------- ----------- ----------- */
/* here we get the coordinate dimensions of the main window */
    GetWindowRect(hwnd, &rc);


/* this makes a quit button at the bottom of the screen */
    ExitButton = CreateWindow( 
        "BUTTON", "Quit", WS_CHILD | 
        WS_VISIBLE | BS_PUSHBUTTON, 
        0, 0,       /* button top left corner x,y */
        50 , 50 ,   /* width & height */
        hwnd, (HMENU)IDC_ExitButton, 
        hInstance, NULL);

    clearScreenButton = CreateWindow( 
        "BUTTON", "Clear", WS_CHILD | 
        WS_VISIBLE | BS_PUSHBUTTON, 
        0, 50,          /* button top left corner x,y */
        50, 50 ,    /* width & height */
        hwnd, (HMENU) IDC_clearScreen,
        hInstance, NULL);

    ShowWindow(hwnd, ncmdshow); 
    UpdateWindow(hwnd);

    while(GetMessage(&msg, NULL, 0, 0))  {       
        TranslateMessage(&msg);                  
        DispatchMessage(&msg); 
   }   
    return msg.wParam;
} /* end WinMain */

/* ----------- ----------- ----------- ----------- */

LRESULT CALLBACK MenuWndProc( 
HWND hwnd,  UINT message, WPARAM wParam,  LPARAM lParam ) 
{           
    /* here we test for what events happened/the user might have done */
    switch (message) 
    {   
        case WM_CREATE: 
            initializeBackground( hwnd );   /* draw the main window */
        break;      
        case WM_DESTROY: 
            PostQuitMessage(0);    
        break;   
        case WM_LBUTTONDOWN:    /* left button pressed / tap on screen */
        break;
        case WM_MOUSEMOVE:      /* mouse pointer is moving */
            /*     if(wParam & MK_LBUTTON)*/
       break;
       case WM_COMMAND:         
            switch(LOWORD(wParam))    
            {       
                case IDC_ExitButton:        /* quit button pressed */
                     PostQuitMessage(0);    
                break;
                case IDC_clearScreen:     /* clear button pressed */
                    InvalidateRect( hwnd, NULL, TRUE); 
                break;      /* wipe the main window */
                default:
                break;          
            }/* end case command */      
        break;  
        case WM_PAINT:
            initializeBackground( hwnd );
        break;      
        default:      
            return DefWindowProc(hwnd, message, wParam, lParam);
        break;      
       }/*  end case message */
    return 0;
}