#include <windows.h>    

// the entry point for any Windows program
int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nShowCmd)
{
        MessageBox(NULL,
               L"Hello World!",
               L"Just another Hello World program!",
               MB_ICONEXCLAMATION | MB_OK);

    
    return 0;
}

#include <windows.h>
#include <windowsx.h>


LRESULT CALLBACK WindowProc(HWND hWnd,
                         UINT message,
                         WPARAM wParam,
                         LPARAM lParam);


int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nCmdShow)
{
    
    HWND hWnd;
  
    WNDCLASSEX wc;

  
    ZeroMemory(&wc, sizeof(WNDCLASSEX));

  
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = (WNDPROC)WindowProc;
    wc.hInstance = hInstance;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
    wc.lpszClassName = "WindowClass1";


    RegisterClassEx(&wc);

  
    hWnd = CreateWindowEx(NULL,
                          "WindowClass1",    
                          "Our First Windowed Program",  
                          WS_OVERLAPPEDWINDOW,    
                          300,    
                          300,    
                          500,    
                          400,    
                          NULL,    
                          NULL,    
                          hInstance,    
                          NULL);    //<--- ERROR HERE

  
    ShowWindow(hWnd, nCmdShow);




    MSG msg;

    while(GetMessage(&msg, NULL, 0, 0))
    {
      
        TranslateMessage(&msg);

        
        DispatchMessage(&msg);
    }

  
    return msg.wParam;
}


LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    // sort through and find what code to run for the message given
    switch(message)
    {
        // this message is read when the window is closed
        case WM_DESTROY:
            {
                // close the application entirely
                PostQuitMessage(0);
                return 0;
            } break;
    }

    // Handle any messages the switch statement didn't
    return DefWindowProc (hWnd, message, wParam, lParam);
}