(function($){   
$.fn.extend({   
        Scroll:function(opt,callback){   
                //参数初始化   
                if(!opt) var opt={};   
                var _btnUp = $("#"+ opt.up);//Shawphy:向上按钮   
                var _btnDown = $("#"+ opt.down);//Shawphy:向下按钮   
                var timerID;   
                var _this=this.eq(0).find("ul:first");   
                var     lineH=_this.find("li:first").height(), //获取行高   
                        line=opt.line?parseInt(opt.line,10):parseInt(this.height()/lineH,10), //每次滚动的行数，默认为一屏，即父容器高度   
                        speed=opt.speed?parseInt(opt.speed,10):500; //卷动速度，数值越大，速度越慢（毫秒）   
                        timer=opt.timer //?parseInt(opt.timer,10):3000; //滚动的时间间隔（毫秒）   
                if(line==0) line=1;   
                var upHeight=0-line*lineH;   
                //滚动函数   
                var scrollUp=function(){   
                        _btnUp.unbind("click",scrollUp); //Shawphy:取消向上按钮的函数绑定   
                        _this.animate({   
                                marginTop:upHeight   
                        },speed,function(){   
                                for(i=1;i<=line;i++){   
                                        _this.find("li:first").appendTo(_this);   
                                }   
                                _this.css({marginTop:0});   
                                _btnUp.bind("click",scrollUp); //Shawphy:绑定向上按钮的点击事件   
                        });   
  
                }   
                //Shawphy:向下翻页函数   
                var scrollDown=function(){   
                        _btnDown.unbind("click",scrollDown);   
                        for(i=1;i<=line;i++){   
                                _this.find("li:last").show().prependTo(_this);   
                        }   
                        _this.css({marginTop:upHeight});   
                        _this.animate({   
                                marginTop:0   
                        },speed,function(){   
                                _btnDown.bind("click",scrollDown);   
                        });   
                }   
               //Shawphy:自动播放   
                var autoPlay = function(){   
                        if(timer)timerID = window.setInterval(scrollUp,timer);   
                };   
                var autoStop = function(){   
                        if(timer)window.clearInterval(timerID);   
                };   
                 //鼠标事件绑定   
                _this.hover(autoStop,autoPlay).mouseout();   
                _btnUp.css("cursor","pointer").click( scrollUp ).hover(autoStop,autoPlay);//Shawphy:向上向下鼠标事件绑定   
                _btnDown.css("cursor","pointer").click( scrollDown ).hover(autoStop,autoPlay);   
  
        }         
})   
})(jQuery);