window.addEvent('domready',function() { 
/* settings */
                var list = $('news-feed').getFirst('ul'); 
                var items = list.getElements('li'); 
                var showDuration = 4000; 
                var scrollDuration = 1500; 
                var index = 0; 
                var height = items[0].getSize().y; 
                
                /* action func */ 
                                var move = function() { 
                                                list.set('tween',{ 
                                                duration: scrollDuration, 
                                                                onComplete: function() { 
                                                                                if(index == items.length - 1) { 
                                                                                                index = 0 - 1; list.scrollTo(0,0);
                                                                                }
                                                                }
                                                }).tween('top',0 - (++index * height)); 
                                }; 
                var alreadyRun = false;
                if(alreadyRun!=true){
                                alreadyRun = true ;
                                move.periodical(showDuration) ; 
                }
});