请按F12自己看~

代码如下：

// 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){
                    $(this).find("li").slice(0, 1).appendTo($(this));
                    $(this).css("margin-top", 0);
                }
            });
        }
        
        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);