void switch_view()
{
    RECT rc;
    SystemParametersInfo(SPI_GETWORKAREA, 0, &rc, NULL);
    DWORD style = GetWindowLongPtr(hwnd, GWL_STYLE);
    if(style & WS_CAPTION)
    {
        SetWindowLongPtr(hwnd, GWL_STYLE, WS_OVERLAPPED);
        SetWindowLongPtr(hwnd, GWL_EXSTYLE, 0);
        SetWindowPos(hwnd, NULL, 0, 0, rc.right, rc.bottom,
            SWP_SHOWWINDOW | SWP_FRAMECHANGED);
    }
    else
    {
        SetWindowLongPtr(hwnd, GWL_STYLE, WS_OVERLAPPEDWINDOW);
        SetWindowPos(hwnd, NULL, 0, 0, 0, 0,
            SWP_SHOWWINDOW | SWP_NOMOVE | SWP_NOSIZE | SWP_FRAMECHANGED);
    }
}