With Me.DataGridView2.Rows(0)
        If CStr(.Cells(0).Value) = "" Or doPoSTP = 0 Then
                        Dim BoxSTP As Object
                        Do
                              BoxSTP = InputBox("Kein Eintrag vorhanden!")
                              If BoxSTP.ToString = "" Then
                                    Exit Do
                              End If
                              If IsNumeric(BoxSTP) Then
                                    .Cells(0).Value = BoxSTP
                                    Exit Do
                              End If
                        Loop
                  End If
  End With