public int NewCart()
 {
     using(var context = new ECommerceDataContext(_connectionString))
     {
         Cart c = new Cart();
         c.DateCreated = DateTime.Now;
         context.Carts.InsertOnSubmit(c);
         context.SubmitChanges();
         return c.CartId;
     }
 }
 partial void UpdateCart(Cart instance);
 partial void DeleteCart(Cart instance);
 partial void InsertCart(Cart instance);