$(function(){
    var timer,
        delay=15000,
        $articles = $('.article-block'),
        $block = $articles.parent(),
        $current = $articles.filter(':first');

    function next_article() {
        var $next = $current.next()
        if ($next.length) {
            $block.animate({'margin-left': '-=797'}, 1000);
            $current = $next
        } else {
            $block.animate({'margin-left': '0'}, 1000);
            $current = $articles.filter(':first')
        }
        resetTimer()
    }

    function prev_article() {
        var $prev = $current.prev()
        if ($prev.length) {
            $block.animate({'margin-left': '+=797'}, 1000);
            $current = $prev
        } else {
            var new_offs = ($articles.length-1) * 797;
            $block.animate({'margin-left': "-"+new_offs}, 1000);
            $current = $articles.filter(':last')
        }
        resetTimer()
    }

    function resetTimer(){
        clearInterval(timer);
        timer = window.setInterval(next_article, delay);
    }
    resetTimer();

    $('.article-prev', $block).click(function(e){
        e.preventDefault();
        prev_article()
    });

    $('.article-next', $block).click(function(e){
        e.preventDefault();
        next_article()
    })
})