Flex applications are stateful, that is, they have the capability to remember data persistently for the duration of the user's session in a way that classic web applications usually don't. The content of an application's data can come from many sources；XML files, databases or other server-side resources. Regardless of how data comes to an application, though, a Flex application stores the data in exactly the same way: as a data model.
Creating a data model:
1.use fx:model