private void DisplayMap_Load(object sender, EventArgs e)
        {
            winformsMap1.BackgroundOverlay.BackgroundBrush = new GeoSolidBrush(GeoColor.GeographicColors.ShallowOcean);
            winformsMap1.MapUnit = GeographyUnit.DecimalDegree;

            TiledWmsLayer tiledWmsLayer = AddTileLayer();
            LayerOverlay staticOverlay = GetStaticLayer();

            staticOverlay.Layers.Add("SimpleWmsLayerPlugin", tiledWmsLayer);
            winformsMap1.Overlays.Add(staticOverlay);
            SetupInitialIconDisplay();
        }

        private TiledWmsLayer AddTileLayer()
        {
            Collection<System.Uri> onsiteServers = new Collection<Uri>();
            onsiteServers.Add(new Uri("http://wmssamples.thinkgeo.com/WmsServer.aspx"));
            TiledWmsLayer tiledWmsLayer = new TiledWmsLayer(onsiteServers);
            tiledWmsLayer.Open();
            foreach (var item in tiledWmsLayer.GetServerLayerNames())
            {
                tiledWmsLayer.ActiveLayerNames.Add(item);
            }

            foreach (var item in tiledWmsLayer.GetServerStyleNames())
            {
                tiledWmsLayer.ActiveStyleNames.Add(item);
            }

            return tiledWmsLayer;
        }

        private static LayerOverlay GetStaticLayer()
        {
            LayerOverlay staticOverlay = new LayerOverlay() { IsBase = true };
            return staticOverlay;
        }

        private void SetupInitialIconDisplay()
        {
            SimpleMarkerOverlay markerOverlay = new SimpleMarkerOverlay() { IsBase = false, MapControl = winformsMap1 };
            winformsMap1.Overlays.Add("IconMarkerOverlay", markerOverlay);
            DrawMarkers(markerOverlay);
        }

        private void DrawMarkers(SimpleMarkerOverlay markeroverlay)
        {
            Random random = new Random();
            for (int i = 0; i < 10; i++)
            {
                Marker marker = new Marker(random.Next(-100, 100), random.Next(-90, 90)) { Name = i.ToString() };
                marker.Image = Properties.Resources.AQUA;
                marker.Tag = "state";
                marker.ToolTipText = "tool tip text";
                SetMarkerProperties(marker);
                markeroverlay.Markers.Add(i.ToString(), marker);
            }
            SetAllMarkerZOrder();
            winformsMap1.Refresh();
        }

        private static void SetMarkerProperties(Marker marker)
        {
            marker.Width = 20;
            marker.Height = 20;
            marker.XOffset = 10;
            marker.YOffset = 10;
        }

        private void SetAllMarkerZOrder()
        {
            MarkerOverlaySortByDisplayState();
        }

        private SimpleMarkerOverlay MarkerOverlaySortByDisplayState()
        {
            GeoCollection<Marker> tmpSortedMarkers = new GeoCollection<Marker>();

            SimpleMarkerOverlay markerOverlay = (SimpleMarkerOverlay)winformsMap1.Overlays["IconMarkerOverlay"];
            foreach (Marker item in markerOverlay.Markers)
            {
                tmpSortedMarkers.Add(item.Name, item);
            }
            markerOverlay.Markers.Clear();
            foreach (Marker item in tmpSortedMarkers)
            {
                markerOverlay.Markers.Add(item.Name, item);
            }
            return markerOverlay;
        }