$('#pane').tabs({tab: 'a', content: '.section'});

// add some events after creating an instance
$('#pane').tabs('addEvent', 'show', function(){
  $(document.body).toggleClass('toggle');
});

$('#pane1').ajaxTabs({
  tab: 'a',
  content: '.section',
  loadingHTML: '<p class=loading>Loading<br><br><img src=loading.gif></p>',
  // or add some events in your options when you first create the instance
  onShow: function(){
    this.container.css('opacity',0.5);
  },
  onAjaxComplete: function(){
    this.container.css('opacity','');
  }
});