Private Sub Workbook_Open()
Dim Datej$, ws As Worksheet, nb As Byte
If MsgBox("voulez-vous créer une nouvelle facture", _
vbYesNo + vbQuestion) = vbNo Then Exit Sub
Datej = Format(Date, "dd_mm_yy")
For Each ws In Sheets
If ws.Name Like Datej & "*" Then
nb = nb + 1
End If
Next
Feuil1.Copy after:=Sheets(Sheets.Count)
With ActiveSheet
If nb = 0 Then
.Name = Datej
Else
.Name = Datej & " (" & nb + 1 & ")"
End If
.Range("E2") = VBA.Date
End With
End Sub