Typical A-task Message Sequence

User Interface		Task
Register with message system
Load task
		Register with message system
		Await message
Send connection request	>
	<	Acknowledge connection request (automatically)
		Wait for next message
Send GSOCC OBEY	>
	<	Acknowledge GSOC OBEY
		Obey user's code

The user's code may, potentially, generate any number of:

	<	Reply with MESSYS__INFORM (output from MSG_OUT(), ERR_FLUSH() etc.)
Display message value to user

or:

	<	Reply with MESSYS__PARAMREQ (Request a prompt for a parameter value)
Prompt User
Reply with MESSYS__PARAMREP	>
		Set parameter value

or:

	<	Reply with MESSYS__SYNC (Output from MSG_SYNC)
Prompt user
Reply with MESSYS__SYNCREP	>

and finally, from the ADAM fixed part:

	<	Reply with terminating message status (DTASK__ACTCOMPLETE is good)
Terminate transaction (automatically)
Display final status if bad.