5. On the other hand, when an existing person's information is entered, you must update the corresponding information in the linked list. BUT only for those fields that are not empty. The intuition being that an empty field means that information is not being changed. Remember, it is possible that all fields have values. You have to determine whether you are updating an existing information or not by actually checking if that person is already present in the system and not by relying on the fields alone.