void album_grp_response(IDictionary<String, object> res)
        {
            object response;

            // getting all photos 
            if (res.TryGetValue("data", out response))
            {
                foreach (JsonObject _post in (JsonArray)response)
                {
                    model = new FacebookItemViewModel(_post);
                    if (model.source_url != null)
                    {
                        AlbumImage image = new AlbumImage();
                        image.source_url = model.source_url;
                        App.albumImages.Add(image);
                    }
                }                
            }                  
         }
        // called when the data is ready form facebook
        void photo_response(IDictionary<String, object> res)
        {
            object response;
            
            // getting all photos 
            if (res!= null && res.TryGetValue("data", out response))
            {
                foreach (JsonObject _post in (JsonArray)response)
                {
                    model = new FacebookItemViewModel(_post);
                    if (model.source_url != null)
                    {
                        // add album image source to allImages collection
                        AlbumImage image = new AlbumImage();
                        image.source_url = model.source_url;
                        hubTileUrl = model.source_url;
                        App.allImages.Add(image);
                     }                    
                }

                this.AllImagesListBox.ItemsSource = App.allImages;
            }
            else {
                    MessageBoxResult m = MessageBox.Show("Facebook null response", "Response", MessageBoxButton.OK);
                 }
        }
        // called when albums are responded.
        void albums_response(IDictionary<String, object> res)
        {
             object response;
             albumIdList = new List<string>();
            // getting all photos 
             if (res != null && res.TryGetValue("data", out response))
             {

                 foreach (JsonObject _post in (JsonArray)response)
                 {
                     model = new FacebookItemViewModel(_post);
                     if (model.id != null)
                     {
                         photoManager.getPhotos(model.id, photo_response);
                         // add hubtile to panorama view when there is an album in facebook
                         album = new HubTile();
                         album.Title = model.name;
                         album.Margin = new Thickness(2, 2, 2, 2);
                         album.GroupTag = model.id;
                         album.Background = new SolidColorBrush(Colors.Green);
                         albumIdList.Add(model.id);
                         // add albums to album specific collection
                         this.AlbumsList.Items.Add(album);
                         // tapping support
                         album.Tap += new EventHandler<System.Windows.Input.GestureEventArgs>(album_Tap);
                     }
                 }
             }
             else
             {
                 MessageBoxResult m = MessageBox.Show("Facebook null album response", "Response", MessageBoxButton.OK);
             }
                      
        }