private List <Placemark> GetPlacemarks(DataTable dt, table_map map)
        {
            List <Placemark> list = new List <Placemark>();

            foreach (DataRow row in dt.Rows)
            {
                ge_data d = new ge_data();
                d.locNorth = get_double("locNorth", row, dt, map);
                d.locEast  = get_double("locEast", row, dt, map);
                d.locLevel = get_double("locLevel", row, dt, map);
            }

            return(list);
        }
        private string get_string(string field2, DataRow row, DataTable dt, table_map map)
        {
            field_map fm = map.field_maps.First(m => m.destination == field2);

            if (fm == null)
            {
                return("");
            }

            if (dt.Columns.Contains(fm.source))
            {
                return(Convert.ToString(row[fm.source]));
            }

            return("");
        }