Reports 2.5 problem

I have a report that has the following before report trigger. The trigger will create a file on the A drive, then check that it was successful.
However it doesn't handle exceptions very well. If there is not disk in drive A the user is informed. If the user presses abort or cancel then the error message below comes up, the user presses ok and the following error messages is displayed :-

REP-1419: 'beforereport': PL/SQL program aborted.

Is there any way of preventing this message from coming up (it will only confuse the users).

function BeforeReport return boolean is
begin

	BEGIN
		GLOBAL_DEFS.Closed_File := TEXT_IO.FOPEN ( 'a:\wedcl.txt', 'W'
);
	EXCEPTION
	WHEN OTHERS
	THEN
		srw.message(100, 'Unable to access file a:\wedcl.txt'); 
   		raise srw.program_abort; 
	END;

	IF NOT TEXT_IO.IS_OPEN ( GLOBAL_DEFS.Closed_File )
	THEN
		srw.message(100, 'Unable to access file a:\wedcl.txt'); 
   		raise srw.program_abort; 
	END IF;

	return (TRUE);

---
Alan Campbell
alan_at_mullen.demon.co.uk