Private Sub btnKRib_Click()
    If VerifChequeKey(edtCheque, edtKeyC) Then
        MsgBox ("Cheque valide" )
    Else
        MsgBox ("Cheque non valide" )
    End If
End Sub
 
Function VerifChequeKey(Number, Key As String) As Boolean
Dim Reste, LenN As Integer
Dim Nb As String
     
    VerifChequeKey = False
    Nb = Number + Key
    Nb = NumC2Num(Nb)
    LenN = Len(Nb)
    Reste = 0
    For i = 1 To LenN
        Reste = (Reste * 10 + Mid(Nb, i, 1)) Mod 97
    Next i
    If Reste = 0 Then VerifChequeKey = True
End Function
 
Function VerifTip(Formule, RIB, Emetteur, Ref, Montant As String) As String
Dim B As Boolean
    VerifTip = ""
     
    If Len(Formule) > 0 Then
        B = VerifPond(Left(Formule, Len(Formule) - 1), Right(Formule, 1), 11)
        If B = False Then
            VerifTip = VerifTip + "1"
        End If
    Else
        VerifTip = VerifTip + "1"
    End If
     
    If Len(RIB) = 23 Then
        B = VerifChequeKey(Left(RIB, Len(RIB) - 2), Right(RIB, 2))
        If (B = False) Then
            VerifTip = VerifTip + "2"
        End If
    Else
        VerifTip = VerifTip + "2"
    End If
     
    If (Len(Emetteur) > 11) And (Len(Emetteur) < 19) Then
        B = VerifPond(Left(Emetteur, Len(Emetteur) - 2), Right(Emetteur, 2), 100)
        If B = False Then
            VerifTip = VerifTip + "3"
        End If
    Else
        VerifTip = VerifTip + "3"
    End If
     
    If (Len(Ref) > 22) And (Len(Ref) < 33) Then
        B = VerifPond(Mid(Ref, 3, Len(Ref) - 7), Left(Ref, 2), 100)
        If B = False Then
            VerifTip = VerifTip + "4"
        End If
    Else
        VerifTip = VerifTip + "4"
    End If
     
    If (Len(Montant) > 0) And (Len(Ref) > 5) Then
        B = VerifPond(Right(Ref, 3) + Format(Montant, "00000000" ), Mid(Ref, Len(Ref) - 4, 2), 100)
        If B = False Then
            VerifTip = VerifTip + "5"
        End If
    Else
        VerifTip = VerifTip + "5"
    End If
End Function
 
Function VerifPond(Numero, Key As String, Modulo As Integer) As Boolean
Dim i, Taille, Total As Integer
 
    VerifPond = False
    Taille = Len(Numero)
 
    For i = 1 To Taille
        Total = Total + CInt(Mid(Numero, i, 1)) * (Taille - i + 1)
    Next i
     
    If CInt(Key) = (Total Mod Modulo) Then VerifPond = True
End Function
 
Private Sub btnVerifTIP_Click()
Dim r As String
     
    r = VerifTip(edtFormule, edtRIB, edtEmetteur, edtReference, edtMontant)
     
    If r = "" Then
        MsgBox ("TIP valide" )
        edtFormule.BackColor = vbWhite
        edtRIB.BackColor = vbWhite
        edtEmetteur.BackColor = vbWhite
        edtReference.BackColor = vbWhite
        edtMontant.BackColor = vbWhite
    Else
        MsgBox ("TIP non Valide (Err n°" + CStr(r) + " )" )
         
        If InStr(1, r, "1" ) Then edtFormule.BackColor = vbRed Else edtFormule.BackColor = vbWhite
         
        If InStr(1, r, "2" ) Then edtRIB.BackColor = vbRed Else edtRIB.BackColor = vbWhite
         
        If InStr(1, r, "3" ) Then edtEmetteur.BackColor = vbRed Else edtEmetteur.BackColor = vbWhite
         
        If InStr(1, r, "4" ) Then
            edtReference.BackColor = vbRed
            'rtxtRef.SelStart = 0
            'rtxtRef.SelLength = (Len(rtxtRef.Text) - 5)
            'rtxtRef.SelColor = vbRed
        Else
            edtReference.BackColor = vbWhite
            'rtxtRef.SelStart = 0
            'rtxtRef.SelLength = Len(rtxtRef.Text)
            'rtxtRef.SelColor = vbBlack
        End If
             
        If InStr(1, r, "5" ) Then
            edtMontant.BackColor = vbRed
            'rtxtRef.SelStart = (Len(rtxtRef.Text) - 5)
            'rtxtRef.SelLength = 5
            'rtxtRef.SelColor = vbRed
        Else
            edtMontant.BackColor = vbWhite
            'rtxtRef.SelStart = 0
            'rtxtRef.SelLength = Len(rtxtRef.Text)
            'rtxtRef.SelColor = vbBlack
        End If
    End If
End Sub
 
Function NumC2Num(Num As String) As String
Dim i, c As Integer
Dim S As String
    Num = Format(Num, ">" )
     
    For i = 1 To Len(Num)
        c = Asc(Mid(Num, i, 1))
        If c > 64 And c < 83 Then
            c = (c Mod 9) - 1
            S = S + CStr(c)
        ElseIf c > 82 And c < 133 Then
            c = (c Mod 9)
            S = S + CStr(c)
        Else
            S = S + Chr(c)
        End If
    Next i
    NumC2Num = S
End Function
 
Private Sub Form_KeyPress(KeyAscii As Integer)
    If (TypeOf ActiveControl Is TextBox) And (KeyAscii = 13) Then
        SendKeys "{TAB}"
        KeyAscii = 0
    End If
End Sub