1	SUB SMG_CHANGE_VIRTUAL_DISPLAY(LONG New_rows,LONG New_cols,	&
		LONG Display_attr,LONG Video_attr,LONG Vir_disp_num)

	!---------------------------------------------------------------&
	!								&
	!		   SMG_CHANGE_VIRTUAL_DISPLAY			&
	!								&
	!		Creation Date:  3-July-1985			&
	!		Author:		Ken Messer			&
	! 		Purpose:        Change the attributes of a	&
	!				virtual display			&
	!								&
	!		Modification history				&
	!								&
	!	Date	Description of change(s)			&
	!								&
	!---------------------------------------------------------------&
	!								&
	! Copyright (c) 1985 -	Ken Messer, Allied Electronics, Inc.,	&
	!			401 E. 8th St., Ft. Worth, TX  76102	&
	!								&
	! This software may be copied and distributed freely to anyone	&
	! for non-commerical use provided that this copyright notice is &
	! included.							&
	!---------------------------------------------------------------&

	OPTION TYPE = INTEGER, SIZE = INTEGER LONG

	%include "SMG$LIBRARY:SMG.DFN"

	DECLARE LONG CONSTANT	True = -1,				&
				False = 0

	DECLARE LONG		Return_status,				&
				Display_attributes,			&
				Video_attributes

	EXTERNAL LONG CONSTANT	SMG$M_Border,				&
				SMG$M_Blink,				&
				SMG$M_Bold,				&
				SMG$M_Reverse,				&
				SMG$M_Underline,			&
				SS$_Normal

	EXTERNAL LONG FUNCTION	SMG$Change_virtual_display

	EXTERNAL STRING FUNCTION	Get_Error_Message(LONG)

	!---------------------------------------------------------------&
	!								&
	!		M a i n   P r o g r a m   L o g i c		&
	!								&
	!---------------------------------------------------------------&
                                                                         
	! Border the display if desired

	IF Display_attr <> 0   THEN
	   Display_attributes = SMG$M_Border
	ELSE
	   Display_attributes = 0
	END IF


	! Set the desired video attributes

	Video_attributes = 0

	Video_attributes = Video_attributes OR SMG$M_Blink		&
		IF Video_attr AND 1

	Video_attributes = Video_attributes OR SMG$M_Bold		&
		IF video_attr AND 2

	Video_attributes = Video_attributes OR SMG$M_Reverse		&
		IF Video_attr AND 4

	Video_attributes = Video_attributes OR SMG$M_Underline		&
		IF Video_attr AND 8


	! Call the SMG RTL routine to change the display

	Return_status = SMG$Change_virtual_display(Display_id(Vir_disp_num), &
		New_rows,New_cols,Display_attributes,Video_attributes)

	! Check for error

	IF Return_status AND SS$_Normal = 0   THEN
		PRINT Get_Error_Message(Return_status)
		STOP
	END IF


	SUBEXIT

	END SUB