최상위 윈도우

LRESULT CALLBACK WndProc(HWND hWnd,UINT iMessage,WPARAM wParam,LPARAM lParam)
{
    switch(iMessage) {
    case WM_LBUTTONDOWN:
        SetWindowPos(hWnd,HWND_TOPMOST,0,0,0,0,SWP_NOMOVE|SWP_NOSIZE);
        return 0;
    case WM_RBUTTONDOWN:
        SetWindowPos(hWnd,HWND_NOTOPMOST,0,0,0,0,SWP_NOMOVE|SWP_NOSIZE);
        return 0;
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return(DefWindowProc(hWnd,iMessage,wParam,lParam));
}