function numroll() {

    $.fn.countto = function (options) {
        options = options || {};

        return $(this).each(function () {
            // set options for current element
            var settings = $.extend({}, $.fn.countto.defaults, {
                from: $(this).data('from'),
                to: $(this).data('to'),
                speed: $(this).data('speed'),
                refreshinterval: $(this).data('refresh-interval'),
                decimals: $(this).data('decimals')
            }, options);

            // how many times to update the value, and how much to increment the value on each update
            var loops = math.ceil(settings.speed / settings.refreshinterval),
                increment = (settings.to - settings.from) / loops;

            // references & variables that will change with each update
            var self = this,
                $self = $(this),
                loopcount = 0,
                value = settings.from,
                data = $self.data('countto') || {};

            $self.data('countto', data);

            // if an existing interval can be found, clear it first
            if (data.interval) {
                clearinterval(data.interval);
            }
            data.interval = setinterval(updatetimer, settings.refreshinterval);

            // initialize the element with the starting value
            render(value);

            function updatetimer() {
                value += increment;
                loopcount++;

                render(value);

                if (typeof(settings.onupdate) == 'function') {
                    settings.onupdate.call(self, value);
                }

                if (loopcount >= loops) {
                    // remove the interval
                    $self.removedata('countto');
                    clearinterval(data.interval);
                    value = settings.to;

                    if (typeof(settings.oncomplete) == 'function') {
                        settings.oncomplete.call(self, value);
                    }
                }
            }

            function render(value) {
                var formattedvalue = settings.formatter.call(self, value, settings);
                $self.html(formattedvalue);
            }
        });
    };

    $.fn.countto.defaults = {
        from: 0,               // the number the element should start at
        to: 0,                 // the number the element should end at
        speed: 1000,           // how long it should take to count between the target numbers
        refreshinterval: 100,  // how often the element should be updated
        decimals: 0,           // the number of decimal places to show
        formatter: formatter,  // handler for formatting the value before rendering
        onupdate: null,        // callback method for every time the element is updated
        oncomplete: null       // callback method for when the element finishes updating
    };


    function formatter(value, settings) {
        return value.tofixed(settings.decimals);
    }


    // custom formatting example
    // $('.timer').data('counttooptions', {
    //     formatter: function (value, options) {
    //         return value.tofixed(options.decimals).replace(/\b(?=(?:\d{3})+(?!\d))/g, ',');
    //     }
    // });

    // start all the timers
    $('.timer').each(count);


    function count(options) {
        var $this = $(this);
        options = $.extend({}, options || {}, $this.data('counttooptions') || {});
        $this.countto(options);
    }


}

var flag = false;
if($('.timer-scroll').length>1){
    var scroll = $('.timer-scroll').offset().top-window.innerheight;
}

//  触发时间
$(window).scroll(function () {
    var height = $(window).scrolltop();
    if (height >= scroll && false === flag) {
        flag = true;
        numroll();
    }
    if (height < scroll) {
        flag = false;
    }
});