private void CommentListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (CommentListView.SelectedItem != null)
            {
                Comment comment = (Comment)CommentListView.SelectedItem;
                CommentListView.SelectedItem = null;

                if (comment.ChannelProfile.ChannelIndex == App.USER_IDX)
                {
                    MessageBoxResult rsltMessageBox = MessageBox.Show("Are you sure to delete this comment?", "Delete comment", MessageBoxButton.YesNo, MessageBoxImage.Question);

                    switch (rsltMessageBox)
                    {
                    case MessageBoxResult.Yes:
                        ViewModel.DeleteComment(comment.Index);
                        break;

                    case MessageBoxResult.No:

                        break;
                    }
                }
            }
        }