integer function tleChk( line )
!
!     Perform the checksum (mod 10) of the first 68 characters of a
!     two-line element text line, and return the difference between
!     the computed checksum and the recorded checksum (character 69).
!
!     B. Knapp, 1999-08-11
!
      implicit none
!
!     Input
      character*69 line
!
!     Local
      character*1 ch
      integer i, sum, chval
!
      sum = 0
      do i=1,68
         ch = line(i:i)
         if ( ch .eq. '-' ) then
            chval = 1
         else if ( ch .lt. '0' .or. '9' .lt. ch ) then
            chval = 0
         else
            read(ch,*) chval
         endif
         sum = sum+chval
      enddo
      ch = line(69:69)
      if ( ch .eq. ' ' ) then
         chval = 0
      else
         read(ch,*) chval
      endif
      tlechk = mod(sum,10)-chval
!
      return
      end