Generara löpnummer i Excel (VBA)

Private Sub button_avbryt_Click()
  Unload Me
End Sub

Private Sub button_reg_Click()
Dim iRow As Long
Dim ws As Worksheet
Set ws = Worksheets("Kundregister")

'hitta första lediga raden
iRow = ws.Cells.Find(What:="*", SearchOrder:=xlRows, _
    SearchDirection:=xlPrevious, LookIn:=xlValues).Row + 1

'generera kundnummer


'tvinga kundnummer
If Trim(kundnr.Value) = "" Then
  kundnr.SetFocus
  MsgBox "Ange ett kundnummer"
  Exit Sub
End If

'tvinga namn
If Trim(namn.Value) = "" Then
  namn.SetFocus
  MsgBox "Ange ett namn"
  Exit Sub
End If

'kopiera in i databas
ws.Cells(iRow, 1).Value = kundnr.Value
ws.Cells(iRow, 2).Value = namn.Value
ws.Cells(iRow, 3).Value = adress.Value
ws.Cells(iRow, 4).Value = postnr.Value
ws.Cells(iRow, 5).Value = postort.Value
ws.Cells(iRow, 6).Value = telefon.Value

'rensa
kundnr.Value = ""
namn.Value = ""
adress.Value = ""
postnr.Value = ""
postort.Value = ""
telefon.Value = ""
namn.SetFocus

End Sub