// event - Drawing of Overlay has Started
        void loTracking_Drawing(object sender, DrawingOverlayEventArgs e)
        {
            Boolean bOutCome;
            string sInform;

            DateTime TheDateTime;
            LayerOverlay TheLayerOverlay;
            clsTrackingLayerOverlayItem oTrackingLayerOverlay;

            // get the time as the Drawing Start Time
            TheDateTime = DateTime.Now;

            // get the LayerOverlay
            TheLayerOverlay = (LayerOverlay)sender;

            // get Tracking LayerOverlay Item
            bOutCome = cTrackingLayerOverlay.TryGetValue(TheLayerOverlay.Name, out oTrackingLayerOverlay);
            if (bOutCome == false)
            {
                sInform = string.Format("Unable to Locate TrackingLayerOverlayItem, LayerOverylay={0}", TheLayerOverlay.Name);
                bOutCome = Variables.gLogInform.LogInform((OriStarTools.UtlLogInform.LogInformFunction.EventLog), "TrackingOverlay.loTracking_Drawing", sInform, EventLogEntryType.Error);
                return;
            }

            // save the Drawing Start Time
            oTrackingLayerOverlay.TheDateTimeDrawing = TheDateTime;

            // indicate drawing InProgress
            oTrackingLayerOverlay.bDrawingInProgress = true;

            return;
        }

        // event - Drawing of Overlay has Ended
        void loTracking_Drawn(object sender, DrawnOverlayEventArgs e)
        {
            Boolean bOutCome;
            string sInform;

            double   TheDrawingTime;
            TimeSpan TheTimeSpanDrawingDrawn;
            DateTime TheDateTime;
            LayerOverlay TheLayerOverlay;
            clsTrackingLayerOverlayItem oTrackingLayerOverlay;

            // get the time as the Drawing End Time
            TheDateTime = DateTime.Now;

            // get the LayerOverlay
            TheLayerOverlay = (LayerOverlay)sender;

            // get Tracking LayerOverlay Item
            bOutCome = cTrackingLayerOverlay.TryGetValue(TheLayerOverlay.Name, out oTrackingLayerOverlay);
            if (bOutCome == false)
            {
                sInform = string.Format("Unable to Locate TrackingLayerOverlayItem, LayerOverylay={0}", TheLayerOverlay.Name);
                bOutCome = Variables.gLogInform.LogInform((OriStarTools.UtlLogInform.LogInformFunction.EventLog), "TrackingOverlay.loTracking_Drawn", sInform, EventLogEntryType.Error);
                return;
            }

            // save the Drawing End Time
            oTrackingLayerOverlay.TheDateTimeDrawn = TheDateTime;

            // calculate the Drawing Time
            TheTimeSpanDrawingDrawn = (oTrackingLayerOverlay.TheDateTimeDrawn - oTrackingLayerOverlay.TheDateTimeDrawing);
            TheDrawingTime = TheTimeSpanDrawingDrawn.TotalMilliseconds;

            // compare to Minimum/Maximum Times
            if (TheDrawingTime < oTrackingLayerOverlay.MinDrawingTime)
            {
                oTrackingLayerOverlay.MinDrawingTime = TheDrawingTime;

                sInform = string.Format("Drawing Time: Overylay={0}, Time={1}, MinTime={2}, MaxTime={3}", TheLayerOverlay.Name, TheDrawingTime, oTrackingLayerOverlay.MinDrawingTime, oTrackingLayerOverlay.MaxDrawingTime);
                bOutCome = Variables.gLogInform.LogInform((OriStarTools.UtlLogInform.LogInformFunction.EventLog), "TrackingOverlay.loTracking_Drawn", sInform, EventLogEntryType.SuccessAudit);
            }
            if (TheDrawingTime > oTrackingLayerOverlay.MaxDrawingTime)
            {
                oTrackingLayerOverlay.MaxDrawingTime = TheDrawingTime;

                sInform = string.Format("Drawing Time: Overylay={0}, Time={1}, MinTime={2}, MaxTime={3}", TheLayerOverlay.Name, TheDrawingTime, oTrackingLayerOverlay.MinDrawingTime, oTrackingLayerOverlay.MaxDrawingTime);
                bOutCome = Variables.gLogInform.LogInform((OriStarTools.UtlLogInform.LogInformFunction.EventLog), "TrackingOverlay.loTracking_Drawn", sInform, EventLogEntryType.SuccessAudit);
            }

            // indicate drawing complete
            oTrackingLayerOverlay.bDrawingInProgress = false;

            return;
        }