Simple Win32 Window

#undef UNICODE
#undef _UNICODE
#include

//
// SIMPLE WINDOW
//

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
switch (msg) {
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
}


int __stdcall WinMain(HINSTANCE hPrevInstance, HINSTANCE hInstance, LPSTR CmdLine, int nCmdShow) {

WNDCLASSEX wc;
int ret=0;

wc.cbClsExtra=0;
wc.cbSize=sizeof(WNDCLASSEX);
wc.cbWndExtra=0;
wc.hbrBackground=(HBRUSH) (COLOR_WINDOW+1);
wc.hCursor=LoadCursor(NULL, IDC_ARROW);
wc.hIcon=LoadIcon(NULL, IDI_APPLICATION);
wc.hIconSm=LoadIcon(NULL, IDI_APPLICATION);
wc.hInstance=hInstance;
wc.lpfnWndProc=WndProc;
wc.lpszClassName="Marshal";
wc.lpszMenuName=NULL;
wc.style=0;

ret = RegisterClassExA(&wc);
if (ret==0) {
MessageBoxA(NULL, "Could not register window class", "Error", MB_OK);
ExitProcess(-1);
}


HWND hwnd;
hwnd = CreateWindowEx(0, "Marshal", "Video Game", WS_OVERLAPPEDWINDOW, 10, 10, 320, 200, NULL, NULL, hInstance, NULL);

if (hwnd==NULL) {
MessageBoxA(NULL, "Could not instantiate window class", "Error", MB_OK);
ExitProcess(-1);
}


ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);


MSG msg;
while (GetMessage(&msg, NULL, 0, 0)>0) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}

return (int) msg.wParam;

}