javascrpt实现间隔性滚动的效果

用法很简单：
var scroll = new ScrollText("content","pre","next",true);
第一个参数是滚动区的id,第二个是显示上一条的按钮的id,第三个是显示下一条的按钮的id,第四个是是否直接开始滚动，为false的话后面再scroll.Start()就OK了。
废话不说了，贴代码吧。
我第一次发贴，不懂排版，直接贴了。
ScrollText.js

function ScrollText(content,btnPrevious,btnNext,autoStart)
{
    this.Speed = 10;
    this.Timeout = 1500;
    this.LineHeight = 20;
    this.NextButton = this.$(btnNext);
    this.PreviousButton = this.$(btnPrevious);
    this.ScrollContent = this.$(content);
    this.ScrollContent.innerHTML += this.ScrollContent.innerHTML;
    this.NextButton.onclick = this.GetFunction(this,"Next");
    this.PreviousButton.onclick = this.GetFunction(this,"Previous");
    
    this.NextButton.onmouseover = this.GetFunction(this,"Stop");
    this.NextButton.onmouseout = this.GetFunction(this,"Start");
    
    this.ScrollContent.onmouseover = this.GetFunction(this,"Stop");
    this.ScrollContent.onmouseout = this.GetFunction(this,"Start");
    
    this.PreviousButton.onmouseover = this.GetFunction(this,"Stop");
    this.PreviousButton.onmouseout = this.GetFunction(this,"Start");
    if(autoStart)
    {
        this.Start();
    }
}

ScrollText.prototype.$ = function(element)
{
    return document.getElementById(element);
}

ScrollText.prototype.Previous = function()
{
    clearTimeout(this.AutoScrollTimer);
    clearTimeout(this.ScrollTimer);
    this.Scroll("up");
}

ScrollText.prototype.Next = function()
{
    clearTimeout(this.AutoScrollTimer);
    clearTimeout(this.ScrollTimer);
    this.Scroll("down");
}