Private Sub From_Load()
  Text1.Text = 0
  Command1.Caption = "Aufwärts"
  Command1.Tag = "Up"
End Sub
 
Private Sub Command1_Click()
  Select Case Command1.Tag
    Case "Up"
      Text1.Text = CLng(Text1.Text) + 1
      If CLng(Text1.Text) = 20 Then
        Command1.Caption = "Abwärts"
        Command1.Tag = "Down"
      End If
    Case "Down"
      Text1.Text = CLng(Text1.Text) - 1
      If CLng(Text1.Text) = 0 Then
        Command1.Caption = "Aufwärts"
        Command1.Tag = "Up"
      End If
  End Select
End Sub

Gruß
Marcus