function show_featured_video(id)
{
  $('.featured_video .featured_video_container').hide();
  $('.featured_video .thumbnail_stamp.now_playing').hide();

  $(id_for(id)).show();
  $(id_for(id) + '_now_playing_stamp').show();
}

function show_join_features_tab(name)
{
  $('.sign_up .site_features .tab').removeClass('active').addClass('inactive');
  $('.sign_up .site_features .tab' + class_for(name)).removeClass('inactive').addClass('active');

  $('.sign_up .site_features .panes div').hide();
  $('.sign_up .site_features .panes ' + class_for(name)).show();
}

/* Helpers. */

function id_for(id)
{
  return(css_identifier('#', id));
}

function class_for(id)
{
  return(css_identifier('.', id));
}

function css_identifier(prefix, id)
{
  return(prefix + id);
}