C--------------------------------------------------------------------------
        subroutine ftclsx(iunit,keep,status)

C       low level routine to close a file
C
C       iunit   i  Fortran I/O unit number
C       keep    l  keep the file? (else delete it)
C       status  i  returned error status (0=ok)
C
C       written by Wm Pence, HEASARC/GSFC, Aug 1992

        integer iunit,status
        logical keep

C       COMMON BLOCK DEFINITIONS:--------------------------------------------
        integer nb,ne
        parameter (nb = 20)
        parameter (ne = 512)

        integer bufnum,chdu,hdutyp,maxhdu,hdstrt,hdend,nxthdr,dtstrt
        integer nxtfld
        logical wrmode
        common/ft0001/bufnum(199),chdu(nb),hdutyp(nb),maxhdu(nb),
     &  wrmode(nb),hdstrt(nb,ne),hdend(nb),nxthdr(nb),dtstrt(nb),nxtfld

        integer buflun,currnt,reclen,bytnum,maxrec
        common/ftlbuf/buflun(nb),currnt(nb),reclen(nb),
     &  bytnum(nb),maxrec(nb)
C       END OF COMMON BLOCK DEFINITIONS-----------------------------------

        integer ibuff

        ibuff=bufnum(iunit)

        if (ibuff .eq. 0)return

C       reset file common block parameters
        bufnum(iunit)=0
        buflun(ibuff)=0
        wrmode(ibuff)=.false.
        currnt(ibuff)=0
        reclen(ibuff)=0
        bytnum(ibuff)=0

        if (keep)then
                close(iunit,err=900)
        else
                close(iunit,status='DELETE',err=900)
        end if
        return

900     continue
C       set error code, if it has not previous been set
        if (status .le. 0)status=110
        end