Private Sub Workbook_BeforeClose(Cancel As Boolean)
Dim myName As String
myName = Sheets("Tabelle1").Range("B1").Value & Format(Date, "DDMMYY")
With ThisWorkbook
If Left(.Name, (InStrRev(.Name, ".", -1, vbTextCompare) - 1)) <> myName Or Not .Saved Then
If MsgBox("Arbeitsmappe speichern", vbQuestion + vbYesNo) = vbYes Then
Application.DisplayAlerts = False
.SaveAs myName, .FileFormat
Application.DisplayAlerts = True
End If
End If
End With
End Sub