private void returnBook(string id, TimeSpan ts)
{
float penalty = 0;
string penaltyMsg = "";
if (ts.Days > 0)
{
penalty = penaltyPerDay * ts.Days;
}
if (penalty > 0)
{
penaltyMsg = "You have been imposed a penality of $" + penalty + ". ";
}
BookControl bc = new BookControl();
bc.returnBook(int.Parse(id), LoginInfo.LoggedInId, penalty);
MessageBox.Show(bc.Message + " " + penaltyMsg);
loadData();
}