hello Don
yes i m using marker and marker code is
InMemoryFeatureLayer routingExtentLayer = new InMemoryFeatureLayer();
routingExtentLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = new AreaStyle(new GeoPen(GeoColor.SimpleColors.Green));
routingExtentLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
routingExtentLayer.InternalFeatures.Add(new Feature(new RectangleShape(-87.9, 15, -83, 9.8)));
MainMap.DynamicOverlay.Layers.Add("RoutingExtentLayer", routingExtentLayer);
InMemoryFeatureLayer newRoutingLayer = new InMemoryFeatureLayer();
newRoutingLayer.ZoomLevelSet.ZoomLevel01.DefaultLineStyle = new LineStyle(new GeoPen(GeoColor.FromArgb(160, GeoColor.SimpleColors.Blue), 4));
newRoutingLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
MainMap.DynamicOverlay.Layers.Add("NewRoutingLayer", newRoutingLayer);
InMemoryMarkerOverlay routeStart = new InMemoryMarkerOverlay("RouteStart");
routeStart.ZoomLevelSet.ZoomLevel01.DefaultMarkerStyle.WebImage = new WebImage("images/dd-start.png", 20, 34, -10f, -34f);
routeStart.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
MainMap.CustomOverlays.Add(routeStart);
InMemoryMarkerOverlay routeEnd = new InMemoryMarkerOverlay("RouteEnd");
routeEnd.ZoomLevelSet.ZoomLevel01.DefaultMarkerStyle.WebImage = new WebImage("images/dd-end.png", 20, 34, -10f, -34f);
routeEnd.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
MainMap.CustomOverlays.Add(routeEnd);