$("#track_" + source_id).addClass("playing_track");
}
else if(state == "paused"){
$("#player_" + current_document).find(".play").get(0).style.display = "inline";
$("#player_" + current_document).find(".pause").get(0).style.display = "none";
$("#player_" + current_document).find(".stop").get(0).style.display = "inline";
$("#track_" + source_id).addClass("playing_track");
}
else if(state == "paused"){
$("#player_" + current_document).find(".play").get(0).style.display = "inline";
$("#player_" + current_document).find(".pause").get(0).style.display = "none";
$("#player_" + current_document).find(".stop").get(0).style.display = "inline";