private void BtnEdit_Clicks(object sender, RoutedEventArgs e)
        {
            this.isEdit = true;
            NewContactClasification v = new NewContactClasification(this);

            v.Show();
        }
        private void BtnNew_Clicks(object sender, RoutedEventArgs e)
        {
            this.isEdit = false;
            bool isWindowOpen = false;

            foreach (Window w in Application.Current.Windows)
            {
                if (w is NewContactClasification)
                {
                    isWindowOpen = true;
                    w.Activate();
                }
            }

            if (!isWindowOpen)
            {
                NewContactClasification period = new NewContactClasification(this);
                period.Show();
            }
        }