Tab.Extra=new Class({Extends:Tab,Binds:['update','start','stop'],initialize:function(options){this.parent(Object.append({interval:10,delay:10,autostart:true},options));this.tabs.each(function(el){el.addEvent('click',function(){this.stop().start.delay(this.options.delay*1000)}.pass(null,this))},this);this.timer=new PeriodicalExecuter(this.update,this.options.interval);if(!this.options.autostart)this.stop();return this},update:function(){return this[this.options.reverse?'previous':'next']()},start:function(){this.timer.registerCallback();return this},stop:function(){this.timer.stop();return this}});