An alternative to using mx:States to add or remove components from your Flex application is to use the Container class addChild (or addChildAt) and removeChild (or removeChildAt) functions. Refer to the Flex 2.0 Language Reference's description of the Container class for complete details.
One of the business rules my login and registration system has to follow is that each user name and email in the system must be unique. If you look back at part 1, I set the databases table up with constraints so that the database will generate an error if an attempt is made to insert a record with a user name or email that already exists in some other record. In this part of my design, I add logic to handle those errors when Flex calls the createMemberService CFC function to add a Member object to the Member table and that Member object has a user name or email that already exists in the table.
