I would suggest investigating the StateMachine and Loadup utilities. Both are capable of doing this, but the approaches are different.
Loadup is a mature and comprehensive utility; focused on this very problem.
StateMachine is focused on controlling transitions between discrete states of your application
Loadup Utility
http://trac.puremvc.org/Utility_AS3_LoadupLoadupAsOrdered Demo
http://trac.puremvc.org/Demo_AS3_LoadupAsOrderedStateMachine Utility
http://trac.puremvc.org/Utility_AS3_StateMachineStateMachine Overview:
http://puremvc.tv/#P003/-=Cliff>