private void renewBook(string id, TimeSpan ts, DateTime dueDate, string timesRenewed) { if (ts.Days > 0) { MessageBox.Show("Sorry you cannot renew the book when its due date has already passed."); return; } if (int.Parse(timesRenewed) >= maxRenewTimes) { MessageBox.Show("Sorry you can only renew a maximum of " + maxRenewTimes + " time(s)."); return; } BookControl bc = new BookControl(); bc.renewBook(int.Parse(id), LoginInfo.LoggedInId, dueDate.AddDays(dueDateExtendDays)); MessageBox.Show(bc.Message); loadData(); }