public void Execute(object parameter)
            {
                TextBlock       item = (parameter as TextBlock);
                SolidColorBrush r    = item.Foreground as SolidColorBrush;

                //MessageBox.Show(r.Color.ToString());
                if (r.Color.ToString().Equals("#FFFF0000"))
                {
                    this.viewModel.ColorText = Colors.Black.ToString();

                    //(parameter as TextBlock).Foreground = new SolidColorBrush(Colors.Black);
                    //remove items in list holiday
                    ListHoliday.Remove(item.Text);
                }
                else
                {
                    this.viewModel.ColorText = Colors.Red.ToString();
                    //(parameter as TextBlock).Foreground = new SolidColorBrush(Colors.Red);
                    //add item in list holiday
                    ListHoliday.Add(item.Text);
                }
            }