(function($){  
$.fn.extend({  
        Scroll:function(opt,callback){  
                  
                if(!opt) var opt={};  
                var _btnUp = $("#"+ opt.up);
                var _btnDown = $("#"+ opt.down);
                var timerID;  
                var _this=this.eq(0).find("ul:first");  
                var     lineH=_this.find("li:first").height(), 
                        line=opt.line?parseInt(opt.line,10):parseInt(this.height()/lineH,10), 
                        speed=opt.speed?parseInt(opt.speed,10):700; 
                        timer=opt.timer 
                if(line==0) line=1;  
                var upHeight=0-line*lineH;  
                
                var scrollUp=function(){  
                        _btnUp.unbind("click",scrollUp); 
                        _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); 
                        });  
 
                }  
            
                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);  
                        });  
                }  
               
                var autoPlay = function(){  
                        if(timer)timerID = window.setInterval(scrollUp,timer);  
                };  
                var autoStop = function(){  
                        if(timer)window.clearInterval(timerID);  
                };  
                  
                _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);  
 
$(document).ready(function(){  
       $("#scrollDiv").Scroll({line:1,speed:700,timer:2000,up:"btn1",down:"btn2"});  
});