Private Function CheckLines(ByVal infile As String, _
    ByVal outfile As String) As Boolean
 
Dim ik%, ak%, zeilev$, zeilep$, fieldsv$(), fieldsp$()
Dim towrite As Boolean
 
On Error GoTo fehler
 
ik = FreeFile
Open infile For Input As #ik
ak = FreeFile
Open outfile For Output As #ak
 
'Erste Zeilenpaarung lesen
Line Input #ik, zeilev
Line Input #ik, zeilep
While Not EOF(ik)
   fieldsv = Split(zeilev, ",")
   fieldsp = Split(zeilep, ",")
   towrite = False
   If CInt(Trim(fieldsv(2))) <> CInt(Trim(fieldsp(2))) Then
      towrite = True
      'Paarung unter Bedingung schreiben
      Print #ak, zeilev
      Print #ak, zeilep
   End If
   'Vorrücken: Prüfzeile wird Zeile davor
   zeilev = zeilep
   If Not EOF(ik) Then
      'Zeile danach lesen (wird Prüfzeile im nächsten Durchgang)
      Line Input #ik, zeilep
    Else
      towrite = False
   End If
   If towrite Then
      'Zeile danach schreiben (falls Bedingung und Zeile vorhanden)
      Print #ak, zeilep
   End If
Wend
 
Close #ik: Close #ak
CheckLines = True
Exit Function
 
fehler:
CheckLines = False
Close #ik: Close #ak
 
End Function