public ActionResult DeleteConfirmed(int id)
        {
            try
            {
                db.UsunCzytelnika(id);
                db.SaveChanges();
                return(RedirectToAction("Index"));
            }
            catch (Exception e)
            {
                string message = "";

                if (e.InnerException == null)
                {
                    message = "Podano nieprawidłowe dane wypozyczenia!";
                }
                else
                {
                    message = e.InnerException.Message;
                }

                TempData["message"] = message;
                return(RedirectToAction("Delete"));
            }

            /*using (var context = new BibliotekaEntities()) {
             *  using (DbContextTransaction dbContextTransaction = context.Database.BeginTransaction(IsolationLevel.ReadUncommitted)) {
             *      try {
             *          context.Database.ExecuteSqlCommand(
             *          @"DELETE FROM Wypozyczenie WHERE Wypozyczenie.IdCzytelnik = " + id);
             *
             *          context.Database.ExecuteSqlCommand(
             *          @"DELETE FROM Czytelnik WHERE Czytelnik.IdCzytelnik = " + id);
             *
             *          context.SaveChanges();
             *
             *          dbContextTransaction.Commit();
             *
             *          return RedirectToAction("Index");
             *      } catch (Exception e) {
             *          string message = "";
             *
             *          if (e.InnerException == null) {
             *              message = "Wystąpił błąd przy usuwaniu czytelnika!";
             *          } else {
             *              message = e.InnerException.Message;
             *          }
             *
             *          TempData["message"] = message;
             *          return RedirectToAction("Delete");
             *      }
             *  }
             * }*/
        }