protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                Map1.MapBackground.BackgroundBrush = new GeoSolidBrush(GeoColor.FromHtml("#E5E3DF"));
                Map1.CurrentExtent = new RectangleShape(-131.22, 55.05, -54.03, 16.91);
                Map1.MapUnit = GeographyUnit.DecimalDegree;

                WorldMapKitWmsWebOverlay worldMapKitOverlay = new WorldMapKitWmsWebOverlay();
                Map1.CustomOverlays.Add(worldMapKitOverlay);

                InMemoryMarkerOverlay markerOverlay = new InMemoryMarkerOverlay("MarkerOverlay", new Collection<FeatureSourceColumn>() { new FeatureSourceColumn("state")});
                //markerOverlay.SuppressingGridSize = 10;
                Random random = new Random();
                for (int i = 0; i < 3000; i++)
                {
                    double xdelt = random.NextDouble() * (131 - 54);
                    double ydelt = random.NextDouble() * (55 - 16);
                    Feature feature = new Feature(-54 - xdelt, 16 + ydelt);
                    if (i % 2 == 0)
                    {
                        feature.ColumnValues.Add("state", "Texas");
                    }
                    else
                    {
                        feature.ColumnValues.Add("state", "California");
                    }
                    markerOverlay.FeatureSource.InternalFeatures.Add(feature);
                }


                MarkerValueItem item1 = new MarkerValueItem("Texas");
                item1.DefaultMarkerStyle = new PointMarkerStyle();
                item1.DefaultMarkerStyle.WebImage = new WebImage("../../theme/default/img/marker_blue.gif", 21, 25);
                item1.DefaultMarkerStyle.WebImage.RotationAngle = 50;

                MarkerValueItem item2 = new MarkerValueItem("California");
                item2.DefaultMarkerStyle = new PointMarkerStyle();
                item2.DefaultMarkerStyle.WebImage = new WebImage("../../theme/default/img/marker_green.gif", 21, 25);
                item2.DefaultMarkerStyle.WebImage.RotationAngle = -50;

                ValueMarkerStyle valueMarkerStyle = new ValueMarkerStyle("state");
                valueMarkerStyle.ValueItems.Add(item1);
                valueMarkerStyle.ValueItems.Add(item2);

                double tolerance = 100;
                ClusterMarkerStyle clusterStyle = new ClusterMarkerStyle(tolerance, 1600, 1200);
                clusterStyle.MarkerStyle = valueMarkerStyle;//pointMarkerStyle;

                markerOverlay.ZoomLevelSet.ZoomLevel01.CustomMarkerStyle = clusterStyle;
                markerOverlay.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
                Map1.CustomOverlays.Add(markerOverlay);
            }
        }