Private Sub Text1_KeyPress(Index As Integer, KeyAscii As Integer)
  Select Case KeyAscii
    Case 13
      ... hatten wir ja schon abgehandelt ;-)
 
    Case 45
      If Left$(Label1(Index), 1) <> "-" Or Text1(Index).SelStart > 0 Then
        KeyAscii = 0
      End If
  End Select
End Sub