function youtubechannel_setvideo(href) {
  youtubeid = href.replace("#","");
  $('#youtubechannel-frame').attr('src','http://www.youtube.com/embed/' + youtubeid);
}

Drupal.behaviors.youtubechannel = function(context) {
  youtubechannel_setvideo($('#youtubechannel-list a:first').attr('href'));
  $('#youtubechannel-list a').click(function(e) {
    youtubechannel_setvideo($(this).attr('href'));
    $(this.attr('class','active');
    return false;
  });
}