map.MapUnit = GeographyUnit.DecimalDegree;
            map.CurrentExtent = new RectangleShape(-180, 90, 180, -90);



            WebImage blueMarkerImage = new WebImage(Url.Content("~/Content/images/marker_blue.gif"), 48, 48, -32, -32);
            blueMarkerImage.Text = "This is blue Marker";
            blueMarkerImage.FontColor = GeoColor.StandardColors.OrangeRed;
            blueMarkerImage.FontStyle = new GeoFont("Arail Black", 12, DrawingFontStyles.Bold);
            MarkerValueItem blueMakerValueItem = new MarkerValueItem("1", new PointMarkerStyle(blueMarkerImage));

            WebImage goldMarkerImage = new WebImage(Url.Content("~/Content/images/marker_gold.gif"), 48, 48, -32, -32);
            goldMarkerImage.Text = "This is gold Marker";
            goldMarkerImage.FontColor = GeoColor.StandardColors.Gold;
            goldMarkerImage.FontStyle = new GeoFont("Arail Black", 7, DrawingFontStyles.Bold);
            MarkerValueItem redMakerValueItem = new MarkerValueItem("2", new PointMarkerStyle(goldMarkerImage));

            ValueMarkerStyle valueMarkerStyle = new ValueMarkerStyle("id");
            valueMarkerStyle.ValueItems.Add(blueMakerValueItem);
            valueMarkerStyle.ValueItems.Add(redMakerValueItem);


            Feature feature1 = new Feature(0, 0);
            feature1.ColumnValues["id"] = "1";
            Feature feature2 = new Feature(0, 50);
            feature2.ColumnValues["id"] = "2";

            map.MarkerOverlay.Features.Add(feature1);
            map.MarkerOverlay.Features.Add(feature2);

            map.MarkerOverlay.Columns.Add(new FeatureSourceColumn("id"));
            map.MarkerOverlay.ZoomLevelSet.ZoomLevel01.CustomMarkerStyle = valueMarkerStyle;
            map.MarkerOverlay.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;