$(document).ready(function () {
    $(function () {
        nav();
    });
    $(window).on('scroll', function () {
        if ($(window).scrolltop() > 100) {
            $('.header_box').removeclass('large').addclass('small');
        } else {
            $('.header_box').removeclass('small').addclass('large');
        }
    });
    function nav() {
        var $licur = $(".navbar>ul>li.cur"),
            curp = $licur.position().left,
            curw = $licur.outerwidth(true),
            $slider = $(".block"),
            $targetele = $(".navbar>ul>li:not('.last')"),
            $navbox = $(".navbar");
        $slider.stop(true, true).animate({
            "left": curp,
            "width": curw
        });
        $targetele.mouseenter(function () {
            var $_parent = $(this);//.parent(),
            _width = $_parent.outerwidth(true),
                posl = $_parent.position().left;
            $slider.stop(true, true).animate({
                "left": posl,
                "width": _width
            }, "fast");
        });
        $navbox.mouseleave(function (cur, wid) {
            cur = curp;
            wid = curw;
            $slider.stop(true, true).animate({
                "left": cur,
                "width": wid
            }, "fast");
        });

    };

});