private void InsertClick(object sender, RoutedEventArgs e)
        {
            MTurma x = new MTurma();

            x.Semestre     = txtSemestre.Text;
            x.IdProfessor  = (Bc.SelectedItem as MProfessor).Id;
            x.IdDisciplina = (Cb.SelectedItem as MDisciplina).Id;
            n.InserirTurma(x);
        }