public class ScreenManager
{

    #region Variables
    private static List<BaseScreen> Screens = new List<BaseScreen>();
    private static List<BaseScreen> NewScreens = new List<BaseScreen>
    #endregion

    public ScreenManager()
    {

    }
 }

private static List<BaseScreen> NewScreens = new List<BaseScreen>

private static List<BaseScreen> NewScreens = new List<BaseScreen>();