Dim c As Range
With Sheets("Acceuil")
If .Range("C7") = "Aucun" And .Range("C8") = "Aucun" Then
Set c = .Range("C7")
ElseIf .Range("C8") = "Aucun" Then Set c = .Range("C8")
Else
Exit Sub
End If
End With
Sheets("Clients").AutoFilter Field:=25, Criteria1:=c.Value