private void toolStripMenuItem1_Click(object sender, EventArgs e)
        {
            try
            {
                IPolyline chain_geom = new PolylineClass();

                ISegmentCollection path1 = new PathClass();

                foreach (Range r in Errors.CenterlineChains[select_chain_name])
                {
                    ISegmentCollection segcoll = r.Shape as ISegmentCollection;
                    path1.AddSegmentCollection(segcoll);
                }

                object obj = Type.Missing;

                IGeometryCollection gCollection = chain_geom as IGeometryCollection;

                gCollection.AddGeometry((IGeometry)path1, obj, obj);

                chain_geom = (IPolyline)gCollection;

                FlashGeometry(chain_geom);
            }
            catch { }
        }