Starting with a Simple Win32 API Window

The Win32 API is the gateway to programming the system APIs and provides classes and functions for activating inbuilt system commands and procedures. The program below creates a simple window allowing the user to set the size, color, icon and other properties. Controls can be set on such windows and functions such as PostMessage and SendMessage can be run on such windows.
#include <windows.h>
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
char szClassName[ ] = "WindowsApp";
int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)
{
    HWND hwnd;
    MSG messages;
    WNDCLASSEX wincl;
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;
    //wincl.style = CS_DBLCLKS;
    wincl.style= CS_HREDRAW | CS_VREDRAW;
    wincl.cbSize = sizeof (WNDCLASSEX);
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;
    wincl.cbClsExtra = 0;
    wincl.cbWndExtra = 0;
    wincl.hbrBackground = (HBRUSH)COLOR_APPWORKSPACE;
    if (!RegisterClassEx (&wincl))
        return 0;

    hwnd = CreateWindowEx (
           0,
           szClassName,
           "Windows App",
           WS_OVERLAPPEDWINDOW,
           CW_USEDEFAULT,
           CW_USEDEFAULT,
           744,
           575,
           HWND_DESKTOP,
           NULL,
           hThisInstance,
           NULL
           );
    ShowWindow (hwnd, nFunsterStil);
    while (GetMessage (&messages, NULL, 0, 0))
    {
        TranslateMessage(&messages);
        DispatchMessage(&messages);
    }
    return messages.wParam;
}
LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
        case WM_DESTROY:
            PostQuitMessage (0);
            break;
        default:
            return DefWindowProc (hwnd, message, wParam, lParam);
    }
    return 0;
}