How do you change the format of a TimeSpan property?

[nickf77]

I have the following code, and I want it to act as a stopwatch.

    Dim spn As New TimeSpan(0, 0, 0)
    Private Sub elapsedtime_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles elapsedtime.Tick
        spn = spn.Add(New TimeSpan(0, 0, 1))
        Label6.Text = String.Format("{1}:{2}", spn.Hours, spn.Minutes, spn.Seconds)
    End Sub

However, when the "stopwatch" ticks, the time is shown like this - 0:3, 2:9, etc. How can I change it so that when the seconds are in the single digits, it shows the time like a normal clock (4:05, 2:09, etc.)?