public void Update(Service.Customer customer)
        {
            Northwind.Data.Customer c = nwindEntity.Customers.Single(
                cust => cust.CustomerID == customer.CustomerID);

            c.CompanyName  = customer.CompanyName;
            c.Address      = customer.Address;
            c.City         = customer.City;
            c.ContactName  = customer.ContactName;
            c.ContactTitle = customer.ContactTitle;
            c.Country      = customer.Country;
            c.Phone        = customer.Phone;
            c.PostalCode   = customer.PostalCode;
            c.Region       = customer.Region;
            nwindEntity.SaveChanges();
        }
        public Customer GetCustomer(string customerID)
        {
            Northwind.Data.Customer c = nwindEntity.Customers.Single(cust => cust.CustomerID == customerID);

            return(new Customer
            {
                CustomerID = c.CustomerID,
                CompanyName = c.CompanyName,
                Address = c.Address,
                City = c.City,
                ContactName = c.ContactName,
                ContactTitle = c.ContactTitle,
                Country = c.Country,
                Phone = c.Phone,
                PostalCode = c.PostalCode,
                Region = c.Region
            });
        }