A retail store has a preferred customer plan where customers may earn discounts on all their purchases. The amount of a customer's discount is determined by the amount of the customer's cumulative purchases in the store.
• When a preferred customer spends $500, he or she gets a 5% discount on all future purchases.
• When a preferred customer spends $1000, he or she gets a 6% discount on all future purchases.
• When a preferred customer spends $1500, he or she gets a 7% discount on all future purchases.
• When a preferred customer spends $2000 or more, he or she gets a 10% discount on all future purchases.
Open the Customer Information project that you modified in Programming Challenge 11. Design a new class named PreferredCustomer, which is derived from the Customer class. The PreferredCustomer class should have the following properties:
• PurchasesAmount (decimal)
• DiscountLevel (single)
Modify the application's form so it allows you to store data in each property of a PreferredCustomer object. Add the object to a collection, using the customer number as a key. Allow the user to look up a preferred customer by the customer number, edit the customer data, and remove a customer from the collection.