private void Universities_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            University     ui = (University)((sender as ListView).SelectedItem);
            UniversityEdit ue = new UniversityEdit(ui);

            ue.ShowDialog();
        }
        private void AddButton_Click(object sender, RoutedEventArgs e)
        {
            UniversityEdit ue = new UniversityEdit();

            ue.ShowDialog();
        }