JavaScript实现连续滚动

 <div id="scrollText">
    <h2>连续滚动示例标题</h2>
      <p>实例新闻，可以添加任何想要滚动的内容。包括图片等等。</p>
      <p><img src="../../images/logo.gif" alt="连续滚动示例图片" width="200" height="60" /></p>
      <p>……</p>
  </div>
<script type="text/javascript">
//添加事件响应函数的函数，与本效果无关
function addEventSimple(obj,evt,fn){
    if(obj.addEventListener){
        obj.addEventListener(evt,fn,false);
    }else if(obj.attachEvent){
        obj.attachEvent('on'+evt,fn);
    }
}
addEventSimple(window,'load',initScrolling);
//保存想要滚动的容器
var scrollingBox;
var scrollingInterval;
//用于记录是否“滚到头”过一次
var reachedBottom=false;
//记录第一次滚到头时候的scrollTop
var bottom;
//初始化滚动效果
function initScrolling(){
    scrollingBox = document.getElementById("scrollText");
    //样式设置，与滚动基本无关，应该用CSS设置。
    scrollingBox.style.height = "60px";
    scrollingBox.style.overflow = "hidden";
    //滚动
    scrollingInterval = setInterval("scrolling()",50);
    //鼠标划过停止滚动效果
    scrollingBox.onmouseover = over;
    //鼠标划出回复滚动效果
    scrollingBox.onmouseout = out;   
}
//滚动效果
function scrolling(){
    //开始滚动,origin是原来scrollTop
    var origin = scrollingBox.scrollTop++;
    //如果到头了
    if(origin == scrollingBox.scrollTop){
        //如果是第一次到头
        if(!reachedBottom){
            scrollingBox.innerHTML+=scrollingBox.innerHTML;
            reachedBottom=true;
            bottom=origin;
        }else{
            //已经到头过，只需回复头接尾的效果
            scrollingBox.scrollTop=bottom;
        }
    }
}
function over(){
    clearInterval(scrollingInterval);
}
function out(){
    scrollingInterval = setInterval("scrolling()",50);
}
  </script>