TESTER LA VALIDITÉ D'UN NUMÉRO DE CARTE DE CRÉDIT

Function CheckNCB(wNCB)
    Dim Total
    Dim ThisN
    
    Dim I
    For I = 1 To Len(wNCB)
        ThisN = Mid(wNCB, I, 1)
    
        If I / 2 = Int(I / 2) Then
            Total = Total + ThisN
            
            
        Else
            
            If ThisN * 2 > 9 Then
                Total = Total + (ThisN * 2 - 9)
            Else
                Total = Total + ThisN * 2
            End If
        End If
    
    Next I
    
    If Total / 10 = Int(Total / 10) Then
        CheckNCB=1
    Else
        CheckNCB=0
    End If

End Function