! If one tries to PUT_VALUE at a prompt stall and the buffer is greater
! than 255 characters, there will be no value put.
!
! The way around this is to use PUT_PORT, but this was meant to be used
! to replace entire records.  To modify just a field, it is almost impossible
! to get DTR to recognize the context of the port's field name.
!
! First, set up the port:

	CALL DTR$COMMAND (DAB, 'DECLARE PORT DATA_PORT USING 
     +					01 DATA_PORT_CONTENTS. 
     +					02 CONTENTS PIC X(1700).;')
	CALL CONTINUE (DAB)

!
! Then declare a dummy variable "X" of sufficient size:

	    CALL DTR$COMMAND (DAB,'DECLARE X PIC X(1700).;')
	    CALL CONTINUE (DAB)

! The repeat clause on DATA_PORT establishes the context for CONTENTS:

	    CALL DTR$COMMAND (DAB,'FOR DATA_PORT X=CONTENTS ;')
	    CALL CONTINUE (DAB)

! Pass the information into the dummy variable:

	    CALL DTR$PUT_PORT (DAB,%REF(LINE(SN,FN)) )
	    CALL CONTINUE (DAB)

! Terminate the loop:

	    CALL DTR$PORT_EOF (DAB)
	    CALL CONTINUE (DAB)

! And modify using the dummy variable:

	    CALL DTR$COMMAND (DAB,'MODIFY USING '//FIELD_NAME(SN,FN)//' = X;')
	    CALL CONTINUE (DAB)


	SUBROUTINE CONTINUE (DUMMY)
!		Calls DTR$CONTINUE using DAB from common block.  It will
!		repeatedly call DTR$CONTINUE until it reaches one of the
!		specified stall points (hard coded).  All messages from 
!		errors are displayed in the status line.
!
!		The ICLEN function returns the position of the last
!		non-blank character in the passed string.

	INCLUDE 'DAB'

	INTEGER*2 CHAN
	COMMON /TERMINAL/ CHAN

	CHARACTER*79 LAST_MESSAGE
	COMMON /LAST_ERROR_MESSAGE/ LAST_MESSAGE

	DO WHILE (DAB$W_STATE .NE. DTR$K_STL_CMD	.AND.
	1	  DAB$W_STATE .NE. DTR$K_STL_PGET	.AND.
	2	  DAB$W_STATE .NE. DTR$K_STL_PPUT	.AND.
	3	  DAB$W_STATE .NE. DTR$K_STL_CONT	.AND.
	4	  DAB$W_STATE .NE. DTR$K_STL_PRMPT		) 

	  IF (DAB$W_STATE .EQ. DTR$K_STL_MSG) THEN

	    IF (MSG_BUFF(1:9).NE.'Statement' .AND.
	1	ICLEN(MSG_BUFF).NE.0) THEN

		CALL PUT_MESSAGE(MSG_BUFF)

	    ENDIF
	  ENDIF

	  CALL DTR$CONTINUE (DAB) 

	END DO	    
	RETURN
	END