public Discount Create(Discount discount)
{
var id = Discounts.Max(c => c.Id);
discount.Id = id;
Discounts.Add(discount);
return discount;
}
public Discount Update(string id, Discount instance)
{
var index = int.Parse(id);
var query = from c in Discounts where c.Id == index select c;
var discount = query.FirstOrDefault();
discount = instance;
return discount;
}