Why the song doesn't play when the next song at the listbox is selected?

This code plays the next song at the listbox

 If AxWindowsMediaPlayer1.playState = WMPLib.WMPPlayState.wmppsStopped Then
        If listTracks.SelectedIndex < listTracks.Items.Count - 1 Then
            listTracks.SelectedIndex = 0
            AxWindowsMediaPlayer1.URL = listTracks.Items(0)
            AxWindowsMediaPlayer1.Ctlcontrols.play()
        Else
            listTracks.SelectedIndex = listTracks.SelectedIndex + 1
            AxWindowsMediaPlayer1.URL = listTracks.Items(listTracks.SelectedIndex)
            AxWindowsMediaPlayer1.Ctlcontrols.play()
        End If
End if

I dont get an error but the next song doesn't play