/// <summary>
    /// Adds a new customer to the current cart.
    /// </summary>
    /// <param name="userid">The GUID UserId of the customer.</param>
    /// <param name="username">The username of the customer.</param>
    /// <param name="firstname">The customer's first name.</param>
    /// <param name="lastname">The customer's last name.</param>
    /// <param name="customeraddress">The customer's address.</param>
    /// <param name="city">The customer's city.</param>
    /// <param name="province">The customer's province.</param>
    /// <param name="postalcode">The customer's postal code.</param>
    /// <param name="phonenumber">The customer's phone number.</param>
    /// <param name="name">The name of the company the customer works for, if appropriate.</param>
    /// <param name="approved">Whether the customer is approved for ordering or not.</param>
    /// <param name="lastactivitydate">The last time the customer interacted with the system.</param>
    /// <returns>The current cart.</returns>
    public static List<CustomerControlCookie> AddItem(Guid userid, string username,
        string firstname, string lastname, string customeraddress, string city,
        string province, string postalcode, string phonenumber, string name,
        bool approved, DateTime lastactivitydate)
    {
        List<CustomerControlCookie> cart = RetrieveCart();
        CustomerControlCookie customer = new CustomerControlCookie();

        customer.UserId = userid;
        customer.FirstName = firstname;
        customer.LastName = lastname;
        customer.UserName = username;
        customer.CustomerAddress = customeraddress;
        customer.City = city;
        customer.Province = province;
        customer.PostalCode = postalcode;
        customer.PhoneNumber = phonenumber;
        customer.Name = name;
        customer.Approved = approved;
        customer.LastActivityDate = lastactivitydate;

        cart.Add(customer);

        return cart;
    }
 public static List<CustomerControlCookie> AddItem(CustomerControlCookie item)
 {
     List<CustomerControlCookie> cart = RetrieveCart();
     cart.Add(item);
     return cart;
 }