C*    SFSIV - INSERT VARIABLE IN LIST
      SUBROUTINE SFSIV (IP, IFRST)
      INCLUDE 'SFSCM.FTN/NOLIIST'
      DIMENSION ID(6)
      EQUIVALENCE (ID,FIDWS)

      DIMENSION INEW(2), ILAV(2), IALPHA(27)
      DIMENSION N2CHR(2)
      EQUIVALENCE (N2CHR(1),NCHRG), (N2CHR(2),ICHR)
      DATA INEW/0,0/, NIN/5/
      DATA IALPHA /36, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 
     1             77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 
     2             90/

C     IF (INDX .EQ. 7) WRITE (6, 700) IP, IFRST, NAVS, IBUF,ID
C700  FORMAT (' ', I4, A2, 5X, I4, 3X, 10A2, 6I5)
      NCHRP = IP - 2
      DO 3 I = 1,27
        IF (IFRST - IALPHA(I)) 3, 4, 3
 3    CONTINUE
      WRITE (NIN, 510) (IBUF(I),I=1,IP/2), INDX
 510  FORMAT (' **ERROR** VARIABLE DOES NOT START WITH A-Z OR $ IN FILE',
     $        I4/11X,'VARAIABLE? ', 9A2)
      CALL SFSEX
 4    LSPTR = IPVEC(I)
      IPS = LSPTR

C   GET NUMBER OF CHARACTERS + FIRST CHAR. FROM VARIABLE NAME LIST

 5    CALL SFS2C (IVARI(IPS), N2CHR)
      IF (ICHR) 10, 60, 10
 10   IF (ICHR - IFRST) 50, 30, 60
 30   NCHRC = MIN0 (NCHRG, NCHRP) - 1
      N = IPS + 1
      IF (NCHRC) 40, 40, 35
 35   IF (JCCHR (IVARI(N),1,NCHRC, IBUF(2),1,NCHRC, 1)-2) 50, 40, 60
 40   IF (NCHRP - NCHRG) 60, 90, 50
 50   LSPTR = IPS
      LNCHG = NCHRG
      IPS = (NCHRG + 2)/2 + IPS
      IPS = IVARI(IPS)
      GO TO 5

C   INSERT AND SET UP POINTERS  FOR NEW VARIABLE

 60   CONTINUE
      IF (NAVSV) 110, 110, 63
 63   IF (IPS - IPVEC(I)) 70, 65, 70
 65   IPVEC(I) = NAVSV
      J = IPS
      GO TO 73
 70   I = (LNCHG + 2)/2 + LSPTR
      J = IVARI(I)
      IVARI(I) = NAVSV
 73   IP = NAVSV*2
      I = (NCHRP + 2)/2 + NAVSV
      NAVSV = I + 3
      IF (NAVSV - MXVAR) 75, 75, 107
 75   CALL SMCHR (NCHRP, 1, IVARI, IP-1, 1)
      CALL SMCHR (IBUF, 2, IVARI, IP, NCHRP)
      IVARI(I) = J
      I = I + 1
 78   IVARI(I) = NAVS*INCLD
      I = I + 1
      IF (INCLD) 110, 110, 80

 80   IVARI(I) = NAVS
      INEW(2) = NR - NROFS(INDX) + NRTOT
      CALL SFS1DW (FIDWS, NAVS, 2, INEW)
      IF (NAVS+1 - MXNAV) 110, 110, 108

C   ATTACH RECORD NO. OF NEW OCCURANCE TO EXISTING VARIABLE NAME

 90   IF (INCLD) 110, 110, 91
 91   I = (NCHRG + 4)/2 + IPS
      J = IVARI(I)
      IF (J) 110, 78, 95
 95   I = I + 1
      NREC = IVARI(I )
C     IF (INDX.EQ.7) WRITE (6,999) NREC,I
C999  FORMAT (10X,2I6)
      CALL SFS1DR(FIDWS, NREC, 2, ILAV)
      IF (ILAV(2) - (NR - NROFS(INDX) + NRTOT)) 105, 110, 105
 105  CONTINUE
      ILAV(1) = NAVS
      NREC = NREC - 1
      CALL SFS1DW (FIDWS, NREC, 2, ILAV)
      GO TO 80

 107  NERC = 1
      GO TO 110
 108  NERC = 2

 110  CONTINUE
      RETURN
      END