I want to be able to validate the fields on a form using the same rules that are used to validate the domain object that represents those Rules ..without having to check each single field that is input with the idea to be able to validate a single field without having to create the whole domain Object. Example: If we have a domain object say Patron String Name String phoneNumber And you have a form with the fields represented as Strings in a request. Name PhoneNumber And if the user enters his phone number I just want to run the rule about phonenumber without firing the rule for name. The first idea was to create a class for each form field which would leverage the power of the rule engine for example: When Patron(phoneNumber not matches " \(?\d{3}\)? ?\d{3}[-.]\d{4}") || PhoneNumber(value not matches " \(?\d{3}\)? ?\d{3}[-.]\d{4}" Then InsertLogical(Message("Bad Phone") But that would mean creating a class for each field, which just seems wrong. Is there a better design? Blair Christie