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Function CheckCard(CCNumber As String) As Boolean
Dim Counter As Integer, TmpInt As Integer Dim Answer As Integer Counter = 1 TmpInt = 0 While Counter <= Len(CCNumber) If IsEven(Len(CCNumber)) Then TmpInt = Val(Mid$(CCNumber, Counter, 1)) If Not IsEven(Counter) Then TmpInt = TmpInt * 2 If TmpInt > 9 Then TmpInt = TmpInt - 9 End If Answer = Answer + TmpInt 'Debug.Print Counter, TmpInt, Answer Counter = Counter + 1 Else TmpInt = Val(Mid$(CCNumber, Counter, 1)) If IsEven(Counter) Then TmpInt = TmpInt * 2 If TmpInt > 9 Then TmpInt = TmpInt - 9 End If Answer = Answer + TmpInt 'Debug.Print Counter, TmpInt, Answer Counter = Counter + 1 End If Wend Answer = Answer Mod 10 If Answer = 0 Then CheckCard = True End Function |