Mit folgender Funktion berechnen Sie den grössten gemeinsamen Teiler zweier Long-Werte l1 und l2:

Public Function GGT(ByVal l1 As Long, ByVal l2 As Long) As Long
Dim max As Long, min As Long, r As Long

  If l1 Then
    If l2 Then
    l1 = Abs(l1)
    l2 = Abs(l2)
      If l1 > l2 Then
        max = l1
        min = l2
      Else
        max = l2
        min = l1
      End If

      Do
        r = max Mod min
        max = min
        min = r
      Loop Until r = 0

    GGT = max
    End If
  End If
End Function