Javascript command to add song to playlist?

Is there a command you can issue to the player from javascript that will add a track to the playlist? I can get the song and ID through tinysong, but I need a add it to a playlist instead of opening a new window.

I'm trying to write a script that will let people request songs through my IRC channel, so obviously I can't have multiple songs playing at once. This would be awesome!

Another option would be to have a way to detect when the song is finished playing, but that's a backup option at best.