ArcGISWindowsPhoneSDK.ViewShed.RemoveLayers_Click C# (CSharp) Method

        private void RemoveLayers_Click(object sender, EventArgs e)
        {
            //remove all previous results
              graphicsLayer.ClearGraphics();

              int idx = MyMap.Layers.Count - 1;
              while (idx > 1)
              {
            MyMap.Layers.RemoveAt(idx);
            idx--;
              }
              _displayViewshedInfo = false;
              MyInfoWindow.IsOpen = false;
        }