C THIS SUBROUTINE OPENS THE BINARY FILE DEFINED BY ARRAY AN
C AND DISPLAYS THE APPROPRIATE PAGE NUMBER DEFINED BY THE
C ARGUMENT IP.
C IP IS SET TO -1 FOR AN INITIAL READIN;  TO 0 TO SWITCH A PAGE
C OFF;	TO AN INTEGER TO DISPLAY THAT PAGE NUMBER;  AND TO -2
C TO CLEAR THE DISPLAY FILES OF THAT MENU.
C
C
	SUBROUTINE MENU(A,B,IP)
	DIMENSION AN(2)
	COMMON/OIL/IVECT(200)
	AN(1)=A
	AN(2)=B
	CALL SEEK(1,AN)
	IF(IP.NE.(-1))GO TO 33
1	READ(1)ITAG
	IF(ITAG.NE.0)GO TO 1
2	READ(1)ISIZ,ITAG,(IVECT(K),K=1,ISIZ)
	IF(ITAG.EQ.0)GO TO 99
	CALL CRT(1,ITAG,IVECT,1,ISIZ)
	GO TO 2
33	IPG=0
3	IPG=IPG+1
	READ(1)ISIZ
	IF(ISIZ.EQ.0)GO TO 99
	IFCN=5
	IF(IPG.EQ.IP)IFCN=4
	IF(IP.EQ.(-2))IFCN=3
	DO 5 I=1,ISIZ
	READ(1)ITAG
5	CALL CRT(IFCN,ITAG)
	GO TO 3
99	CALL CLOSE(1)
	RETURN
	END
