var Scroll = new function(){
    this.delay   = 5000;    //延迟的时间
    this.height  = 20;      //行的高度
    this.step    = 4;       //步长
    this.curHeight= 0;
    this.stimer  = null;
    this.timer   = null; 
    this.start   = function(){ //开始翻页-调用move方法
        this.move();
    }
    this.move  = function(){
        var self = this;
        if(this.curHeight == this.height)       //如果显示完一行
        {
            this.timer = setTimeout(function(){ //使用定时器-定时下一行的翻页时间
            self.move();
        }, this.delay);
        this.curHeight = 0;
        if(this.element.scrollTop >= this.element.scrollHeight - this.height){ //滚动信息已经完毕
        this.element.scrollTop = 0;
        }
        return true;
        }
        this.element.scrollTop += this.step;
        this.curHeight += this.step;
        this.timer = setTimeout(function(){   //设置自动翻页定时器
        self.move();
        }, 30);
    }
    this.stop = function(){        //清除定时期，停止滚动翻页
        clearTimeout(this.timer);
    }
}