Public Function code128$(chaine$)
  'This function is governed by the GNU Lesser General Public License (GNU LGPL)
  'V 2.0.0
  'Parameters : a string
  'Return : * a string which give the bar code when it is dispayed with CODE128.TTF font
  '         * an empty string if the supplied parameter is no good
  Dim i%, checksum&, mini%, dummy%, tableB As Boolean
  code128$ = ""
  
  If Len(chaine$) > 0 Then
  'Check for valid characters
    For i% = 1 To Len(chaine$)
      Select Case Asc(Mid$(chaine$, i%, 1))
      Case 32 To 126, 203
      Case Else
        i% = 0
        Exit For
      End Select
    Next
    'Calculation of the code string with optimized use of tables B and C
    code128$ = ""
    tableB = True
    If i% > 0 Then
      i% = 1 'i% become the string index
      Do While i% <= Len(chaine$)
        If tableB Then
          'See if interesting to switch to table C
          'yes for 4 digits at start or end, else if 6 digits
          mini% = IIf(i% = 1 Or i% + 3 = Len(chaine$), 4, 6)
          GoSub testnum
          If mini% < 0 Then 'Choice of table C
            If i% = 1 Then 'Starting with table C
              code128$ = Chr$(210)
            Else 'Switch to table C
              code128$ = code128$ & Chr$(204)
            End If
            tableB = False
          Else
            If i% = 1 Then code128$ = Chr$(209) 'Starting with table B
          End If
        End If
        If Not tableB Then
          'We are on table C, try to process 2 digits
          mini% = 2
          GoSub testnum
          If mini% < 0 Then 'OK for 2 digits, process it
            dummy% = Val(Mid$(chaine$, i%, 2))
            dummy% = IIf(dummy% < 95, dummy% + 32, dummy% + 105)
            code128$ = code128$ & Chr$(dummy%)
            i% = i% + 2
          Else 'We haven't 2 digits, switch to table B
            code128$ = code128$ & Chr$(205)
            tableB = True
          End If
        End If
        If tableB Then
          'Process 1 digit with table B
          code128$ = code128$ & Mid$(chaine$, i%, 1)
          i% = i% + 1
        End If
      Loop
      'Calculation of the checksum
      For i% = 1 To Len(code128$)
        dummy% = Asc(Mid$(code128$, i%, 1))
        dummy% = IIf(dummy% < 127, dummy% - 32, dummy% - 105)
        If i% = 1 Then checksum& = dummy%
        checksum& = (checksum& + (i% - 1) * dummy%) Mod 103
      Next
      'Calculation of the checksum ASCII code
      checksum& = IIf(checksum& < 95, checksum& + 32, checksum& + 105)
      'Add the checksum and the STOP
      code128$ = code128$ & Chr$(checksum&) & Chr$(211)
    End If
  End If
  Exit Function
testnum:
  'if the mini% characters from i% are numeric, then mini%=0
  mini% = mini% - 1
  If i% + mini% <= Len(chaine$) Then
    Do While mini% >= 0
      If Asc(Mid$(chaine$, i% + mini%, 1)) < 48 Or Asc(Mid$(chaine$, i% + mini%, 1)) > 57 Then Exit Do
      mini% = mini% - 1
    Loop
  End If
Return
End Function