A simple window

#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;    
  /* The Window structure */
  wincl.hInstance = hThisInstance;
  wincl.lpszClassName = szClassName;
  wincl.lpfnWndProc = WindowProcedure;   
  wincl.style = CS_DBLCLKS;        
  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_BACKGROUND;
  
  if (!RegisterClassEx (&wincl))
    return 0;
 
  hwnd = CreateWindowEx (
      0,         
      szClassName,    
      "Windows App",   
      WS_OVERLAPPEDWINDOW, 
      CW_USEDEFAULT,    
      CW_USEDEFAULT,   
      544,        
      375,        
      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;
}