public int AddCustomer(string name, string note, string address, string telephone)
 {
     Customer newCustomer = new Customer
     {
         Name = name,
         Note = note,
         Address = address,
         Telephone = telephone
     };
     db.Customers.InsertOnSubmit(newCustomer);
     Save();
     return newCustomer.Id;
 }
 partial void DeleteCustomer(Customer instance);
 partial void UpdateCustomer(Customer instance);
 partial void InsertCustomer(Customer instance);