protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                Map1.MapBackground.BackgroundBrush = new GeoSolidBrush(GeoColor.FromHtml("#E5E3DF"));
                Map1.CurrentExtent = new RectangleShape(-13939426.6371, 6701997.4056, -7812401.86, 2626987.386962);
                Map1.MapUnit = GeographyUnit.Meter;

                Map1.CustomOverlays.Add(new GoogleOverlay("BackgroundOverlay"));
            }
        }

        protected void btnThinkGeo_Click(object sender, EventArgs e)
        {
            if (Map1.CustomOverlays.Contains("BackgroundOverlay"))
            {
                Map1.CustomOverlays.Remove("BackgroundOverlay");
            }

            BingMapsOverlay bingMapsOverlay = new BingMapsOverlay("BackgroundOverlay");
            bingMapsOverlay.MapType = BingMapsStyle.Road;
            Map1.CustomOverlays.Add(bingMapsOverlay);
        }

        protected void btnGoogle_Click(object sender, EventArgs e)
        {
            if (Map1.CustomOverlays.Contains("BackgroundOverlay")){
                Map1.CustomOverlays.Remove("BackgroundOverlay");
            }

            GoogleOverlay google = new GoogleOverlay ("BackgroundOverlay");
            google.GoogleMapType = GoogleMapType.Normal;
            Map1.CustomOverlays.Insert(0, google );
        }

        protected void btnAddShape_Click(object sender, EventArgs e)
        {
            if (Map1.CustomOverlays.Contains("staticOverlay"))
            {
                Map1.CustomOverlays.Remove("staticOverlay");
            }

            ShapeFileFeatureLayer worldLayer = new ShapeFileFeatureLayer(MapPath("~/SampleData/world/cntry02.shp"));
            worldLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
            worldLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = AreaStyles.CreateSimpleAreaStyle(GeoColor.SimpleColors.Transparent, GeoColor.FromArgb(100, GeoColor.SimpleColors.Red));

            // convert the projection from EPSG 4326 to 900913(google)
            Proj4Projection pro4 = new Proj4Projection();
            pro4.InternalProjectionParametersString = Proj4Projection.GetDecimalDegreesParametersString();
            pro4.ExternalProjectionParametersString = Proj4Projection.GetGoogleMapParametersString();
            pro4.Open();
            worldLayer.FeatureSource.Projection = pro4;

            LayerOverlay staticOverlay = new LayerOverlay("staticOverlay");
            // make sure 'IsBaseOverlay' is false.
            staticOverlay.IsBaseOverlay = false;
            staticOverlay.Layers.Add(worldLayer);
            Map1.CustomOverlays.Add(staticOverlay);
            
        }