' *** BOX_REV.LST *** 2nd GFA-Manual, page 20-24 > PROCEDURE box_reverse(x1,y1,x2,y2) ' ' *** Invert box (e.g. to tell user that option has been chosen) ' *** Call Procedure again (with same parameters) to restore original box ' GRAPHMODE 3 DEFFILL 1,1 BOUNDARY 0 PBOX x1,y1,x2,y2 BOUNDARY 1 GRAPHMODE 1 RETURN ' ********* '