public void deleteAuthor(int id)
        {
            TacGia e = db.TacGias.SingleOrDefault(x => x.MaTacGia == id);

            db.TacGias.Remove(e);
            db.SaveChanges();
        }
 public void createAuthor(TacGia e)
 {
     db.TacGias.Add(e);
     db.SaveChanges();
 }