Create 3 layers named "lables", "actions" and "content."
Insert keyframes (F6) in all 3 layers at frames 1, 5 and 9.
Bring up the 'frame label' tab (modify>frame>label) for each of the keyframes in the "lables" layer and name these 'start', 'valid' and 'invalid.'
Insert 'stop' actions at each keyframe in the "actions" layer.
What we've done:
We have set up the timeline to give us 3 seperate 'screens.'
The start 'screen' will hold the form into which the user will enter their information.
The valid 'screen' will tell the user his information has been sucessfully sent.
The invalid 'screen' will report errors to the user.