#include <windows.h>

#define ID_TIMER 1

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) 
{
    static TCHAR     szAppName[] = TEXT("Beeper1"); 
    HWND             hwnd; 
    MSG              msg; 
    WNDCLASS         wndclass;

    wndclass.style          
 
= CS_HREDRAW | CS_VREDRAW;
    wndclass.lpfnWndProc    = WndProc;
    wndclass.cbClsExtra     = 0;
    wndclass.cbWndExtra     = 0;
    wndclass.hInstance      = hInstance;
    wndclass.hIcon          = LoadIcon(NULL, IDI_APPLICATION);
    wndclass.hCursor        = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground  
 
= (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName   = NULL;
    wndclass.lpszClassName  = szAppName;

    if(!RegisterClass(&wndclass)) {
        MessageBox(NULL, TEXT("This program requires Windows NT !"), szAppName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(szAppName, TEXT("
 
Beeper1 Timer Demo"),
                        WS_OVERLAPPEDWINDOW,
                        CW_USEDEFAULT, CW_USEDEFAULT,
                        CW_USEDEFAULT, CW_USEDEFAULT,
                        NULL, NULL, hInstance, NULL);

    ShowWindow(hwnd, iCmdShow);
    UpdateWindow(hwnd);

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

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) 
{
    static BOOL        fFlipFlop = FALSE;
    HBRUSH             hBrush;
    HDC                hdc;
    PAINTSTRUCT        ps;
    RECT               rc;
    
    switch(message) 
    {
    case WM_CREATE:
        SetTimer(hwnd, ID_TIMER, 1000, NULL);
        return 0;
        
    case WM_TIMER:
        MessageBeep(-1);
        fFlipFlop = !fFlipFlop;
        InvalidateRect(hwnd, NULL, FALSE);
        return 0;
    
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        
        GetClientRect(hwnd, &rc);
        hBrush = CreateSolidBrush(fFlipFlop?RGB(255,0,0):RGB(0,0,255));
        FillRect(hdc, &rc, hBrush);
        
        EndPaint(hwnd, &ps);
        DeleteObject(hBrush);
        return 0;
        
    case WM_DESTROY: 
        KillTimer(hwnd, ID_TIMER);
        PostQuitMessage(0);
        return 0;            
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}