window.addEvent( 'domready', function() {
	var elems = $$( '.mainGallery div ul li' );
	var size = elems.length;
	if( size > 0 ) {
		elems.each( function( item, index ) {
			if( index > 0 ) item.fade( 'hide' );
			else item.fade( 'show' );
		});
		var index = 0;
		// periodical
		var fx = function() {
			elems[index].fade( 'out' );
			if( index == size - 1 ) index = 0;
			else index++;
			elems[index].fade( 'in' );
		};
		periodical = fx.periodical( 5000 );

		$$( '.mainGallery a.prev' )[0].addEvent( 'click', function( e ) {
			new Event.stop( e );
			$clear( periodical );
			elems[index].fade( 'out' );
			if( index == 0 ) index = size - 1;
			else index--;
			elems[index].fade( 'in' );
			periodical = fx.periodical( 5000 );
		});

		$$( '.mainGallery a.next' )[0].addEvent( 'click', function( e ) {
			new Event.stop( e );
			$clear( periodical );
			elems[index].fade( 'out' );
			if( index == size - 1 ) index = 0;
			else index++;
			elems[index].fade( 'in' );
			periodical = fx.periodical( 5000 );
		});
	}
});