private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            Settings settings = new Settings();

            if (settings.AskonStart)
            {
            }
            else
            {
                if (settings.DefaultTool == "Guis/Scientific_Calckit.xaml")
                {
                    scientific.Show();
                    scientific.Activate();
                }
                else if (settings.DefaultTool == "Guis/DigitalWindow.xaml")
                {
                    digital.Show();
                    digital.Activate();
                }
                Close();
            }
        }