Private mCountdown As Integer = 15
 
    Private Sub tmrCountdown_Tick(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles tmrCountdown.Tick
        If mCountdown > 0 Then
            mCountdown -= 1
            lblCountdown.Text = mCountdown.ToString
        Else
            'z.B. Programm beenden.
        End If
    End Sub