public ICommand CreateCommand()
        {
            ICommand ret = null;
            using (AddRoadDialog dlg = new AddRoadDialog())
            {
                if (dlg.ShowDialog() == DialogResult.OK)
                {
                    ret = new AddRoadCommand(app, parent, dlg.RoadName, dlg.HalfWidth);
                }
            }

            return ret;
        }
        public ICommand CreateCommand()
        {
            ICommand ret = null;

            using (AddRoadDialog dlg = new AddRoadDialog())
            {
                if (dlg.ShowDialog() == DialogResult.OK)
                {
                    ret = new AddRoadCommand(app, parent, dlg.RoadName, dlg.HalfWidth);
                }
            }

            return(ret);
        }