// javascript document
(function ($) {
    $.fn.myscroll = function (options) {

        //默认配置
        var defaults = {
            speed: 40,  //滚动速度,值越大速度越慢
            rowheight: 24 //每行的高度
        };

        var opts = $.extend({}, defaults, options), intid = [];

        function marquee(obj, step) {
      
            obj.find("ul").animate({
                margintop: '-=1'
            }, 0, function () {
                var s = math.abs(parseint($(this).css("margin-top")));
                if (s >= step) {
                   
                    $(this).css("margin-top", 0);
                    marquee(obj, step);
                }
            });
        }

        this.each(function (i) {
            var sh = opts["rowheight"], speed = opts["speed"], _this = $(this);
            intid[i] = setinterval(function () {
                if (_this.find("ul").height() <= _this.height()) {
                    clearinterval(intid[i]);
                } else {
                    marquee(_this, sh);
                }
            }, speed);

            _this.hover(function () {
                clearinterval(intid[i]);
            }, function () {
                intid[i] = setinterval(function () {
                    if (_this.find("ul").height() <= _this.height()) {
                        clearinterval(intid[i]);
                    } else {
                        marquee(_this, sh);
                    }
                }, speed);
            });

        });

    }

})(jquery);