	DIMENSION A(500)
	REAL MED
C	INITIALIZE VARIABLES TO ZERO.
	ST=0
	FM=0
	N=0
	MED=0
10	WRITE(5,15)	
15	FORMAT(1X,' IDA#  '$)
	READ(5,20)R
20	FORMAT(A4)
	IF(R.EQ.'NODA')GO TO 50
	IF(R.EQ.'MEAN')GO TO 60
	IF(R.EQ.'STDV')GO TO 70
	IF(R.EQ.'MEDN')GO TO 80
	IF(R.EQ.'NFIL')GO TO 90
	IF(R.EQ.'EODA')GO TO 100
C	IF USER DOES NOT ENTER A VALID COMMAND, PRINT THE FOLLOWING.
	WRITE(5,40)
40	FORMAT(1X,' YOU HAVE MADE AN ERROR. PLEASE INPUT ONE OF THE '/
     C' FOLLOWING COMMANDS:'/
     C' NODA: RETURNS THE NUMBER OF DATA POINTS IN THE FILE'/
     C' MEAN: RETURNS THE AVERAGE OF THE DATA'/
     C' STDV: RETURNS THE STANDARD DEVIATION OF THE DATA'/
     C' MEDN: RETURNS THE MEDIAN OF THE DATA'/
     C' EODA: SIGNALS END OF THE ANALYSIS SESSION'/
     C' NFIL: SIGNALS DESIRE TO INPUT A NEW FILE NAME'/)
	GO TO 10
C	THE FOLLOWING WILL CALL THE APPROPRIATE SUBROUTINE.
50	CALL NODA(A,N)
	GO TO 10
60	CALL MEAN(A,FM)
	GO TO 10
70 	CALL STDV(A,ST)
	GO TO 10
80	CALL MEDN(A,MED)
	GO TO 10
90	CALL NFIL(A,N,FM,ST,MED)
	GO TO 10
100	CALL CLOSE(1)
	STOP 
	END
