window.addEvent('domready',function(){

	// selectors
	var navi=$$('li');
	var blocks=$$('.ac');

	// navi
	navi.addEvent('click',function(el){

		$clear(prd);

		navi.set('class','normal');
		blocks.setStyle('display','none');

		$('ac'+this.get('lang')).setStyle('display','block');
		this.set('class','selected');

	});

	// periodical
	var current=2;
	function switchTab(){
		if(current>5) {
			current=1;
		}

		navi.set('class','normal');
		blocks.setStyle('display','none');

		$('ac'+current).setStyle('display','block');
		$('li'+current).set('class','selected');

		current++;
	}

	var prd=switchTab.periodical(5000,current);

});