C SUBROUTINE TO LOOK AFTER INTERSECTIONS
C				BY S. MIDDLESTADT
C				   DEPT. OF SYSTEMS DESIGN
	SUBROUTINE SET
	COMMON/INTERN/ISW1,ISW2,ISW3,ISW4,ISW5,X,Y,XSTART,
	1XEND,YSTART,YEND,XBEGIN,YBEGIN,XFINAL,YFINAL
	IF(ISW4.EQ.1)GO TO 11
	IF(ISW4.EQ.2)GO TO 20
	IF(ISW1.EQ.1)GO TO 10
	IF(ISW2.EQ.1)GO TO 20
10	ISW5=1
11	XSTART=X
	YSTART=Y
	ISW4=2
	GO TO 30
20	XEND=X
	YEND=Y
	ISW5=1
30	RETURN
	END