// JavaScript Document
(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);