Here's an extended version of the Flex Cookbook recipe I posted the other day.
The Flex 2 ViewStack and TabNavigator controls make it easy to manage multiple views in a Flex 2 application. Each view container becomes a child of the ViewStack (which is the superclass of the TabNavigator). You can access a specific view by index using the selectedIndex property, or by matching against the view object itself using the selectedChild property.
However I don't like to use index values to identify the views. Index values might change if the order of the views changes. Index values have no real meaning so they are hard to remember. I prefer to set up a method that lets other components or code request a view change by a meaningful name, like the id of the view. That way the other components or code in the application don't need to care about the order of the views in the ViewStack; they just need to know the id of the view to show.