private void AddSemestrNameCommand(object parameter)
        {
            DataClasses1DataContext context = new DataClasses1DataContext();
            var semestr = new Semestr
            {
                Semestr_Nazwa = _semestrName
            };
            context.Semestrs.InsertOnSubmit(semestr);
            context.SubmitChanges();

            Window frm = (Window)parameter;
            frm.Close();
        }
 partial void UpdateSemestr(Semestr instance);
 partial void DeleteSemestr(Semestr instance);
 partial void InsertSemestr(Semestr instance);