For Na = 4 To 23 Step 2 If Cells(Lig, Na) = "" Then _
MsgBox "Actuellement, il reste " & 10 - ((Na - 3) \ 2) & " achats à effectuer" & vbCr _
& "Montant total achat = " & Format(MtAchat, "#,##0.00") & vbCr _
& "Remise = " & Format(MtRemise, "#,##0.00"), vbInformation, "REMISE POTENTIELLE": Exit For
Next