Audio player using roAudioPlayer not working

I'm using the following code to play audio, but it's not working. I've even put the code on Task, but no sound either. Wha am I doing wrong? Thanks for your help!

    audioPlayer = CreateObject("roAudioPlayer")
    port = CreateObject("roMessagePort")
    audioPlayer.SetMessagePort(port)
    song = CreateObject("roAssociativeArray")
    song.url = m.top.programURL
    audioplayer.addcontent(song)
    audioplayer.setloop(false)
    audioPlayer.play()