public void Execute()
{
IDialog dialog = factory.CreateDialog();
loan = GetLoan(dialog);
oldInterestRate = loan.interestRateProperty;
List <string> args = new List <string>();
args.Add("Enter new interest rate: ");
newInterestRate = Double.Parse(dialog.ShowDialogSingle(args));
loan.ChangeInterestRate(newInterestRate);
}
public void Undo()
{
loan.ChangeInterestRate(oldInterestRate);
}