前天见到sin100看到的那个日本网站的滚动，挖掘后原来是使用Ajax读取xml后显示出来的。

就弄了这个滚动经典最新话题的供朋友参考参考。
范例使用了prototype.js的ajax轻便型框架。
因为远程调用了 prototype.js 这个文件，测试的朋友请耐心等候一下下。

经典不允许远程调用别的站点的js文件，所以还请多一部操作，复制到本地运行查看结果。
代码如下：

!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"
html xmlns="http://www.w3.org/1999/xhtml" xml:lang="gb2312" 
head
    meta http-equiv="content-type" content="text/html; charset=gb2312" /
    meta name="author" content="Smiling Dolphin" /
    meta name="keywords" content="design, css, cascading, style, sheets, xhtml, graphic design, w3c, web standards, visual, display, java, javascript, c++, php, jsp, asp, py, pl" /
    meta name="description" content="my favorites language." /
    meta name="robots" content="all" /
    titleDolphin Document/title

    style type="text/css" title="currentStyle" media="screen"
        #scroll{width:99%;height:25px;border:1px solid #2BBB00;background:#E7FFE0;overflow:hidden;}
        #scrollFrame,#scrollFrame2{line-height:25px;font-size:13px; word-break:keep-all;line-break:normal; white-space:nowrap;}
        #scrollFrame span,#scrollFrame2 span{display:inline;margin-right:20px;}
    /style
    script src="http://prototype.conio.net/dist/prototype-1.4.0.js" type="text/javascript"/script
/head
body
div id="scroll"
    div id="scrollFrame"/div
    div id="scrollFrame2"/div
/div
script language="javascript" type="text/javascript"

var Ticker = Class.create();
Ticker.prototype = {
    initialize: function() {
        try{
        this.scrollType = "normal";
        this.m_scroll = $(arguments[0]);
        this.m_scroll_1 = $(arguments[1]);
        this.m_scroll_2 = $(arguments[2]);
        this.m_speed = (arguments[3][0])?arguments[3][0]:3;
        this.m_request = (arguments[3][1])?arguments[3][1]:60;
        this.m_loop = (arguments[3][2])?arguments[3][2]:0.05;
        this.m_url = (arguments[3][3])?arguments[3][3]:'http://bbs.blueidea.com/rss.php?fid=1';
        }catch(e){}
        finally{}
        Event.observe(this.m_scroll, 'mouseover', this.mouseover.bindAsEventListener(this), false);
        Event.observe(this.m_scroll, 'mouseout',  this.mouseout.bindAsEventListener(this), false);
        new PeriodicalExecuter(this.scroll.bindAsEventListener(this), this.m_loop);
        new PeriodicalExecuter(this.load.bindAsEventListener(this),   this.m_request);
        this.load();
    },
    load:function(){
        var request = new Ajax.Request(
          this.m_url,
          {
            method:    'post',
            onSuccess: this.update.bindAsEventListener(this),
            onFailure: false,
            on304:     false
          }
        );
    },
    update:function(request){
        var items = request.responseXML.getElementsByTagName("item");
        for(var i=0;iitems.length;i++){

            var title = items[i].childNodes[0].childNodes[0].nodeValue;
            var link = items[i].childNodes[1].childNodes[0].nodeValue;
            var description = items[i].childNodes[2].childNodes[0].nodeValue;
            var author = items[i].childNodes[4].childNodes[0].nodeValue;
            this.m_scroll_1.innerHTML += "spana href=""+link+"" title=""+author+"：rn"+description+"""+i+"："+title+"/a/span";
        }
        this.m_scroll_2.innerHTML = this.m_scroll_1.innerHTML;
    },
    scroll:function(event){
        switch(this.scrollType){
            case "slow":
                if(this.m_scroll_2.offsetWidth-this.m_scroll.scrollLeft=0){
                    this.m_scroll.scrollLeft -= this.m_scroll_1.offsetWidth;
                }else{
                    this.m_scroll.scrollLeft++;
                }
            break;
            case "normal":
            default:
                if(this.m_scroll_2.offsetWidth-this.m_scroll.scrollLeft=0){
                    this.m_scroll.scrollLeft -= this.m_scroll_1.offsetWidth;
                }else{
                    this.m_scroll.scrollLeft+=3;
                }
            break;
        }
    },
    mouseover:function(){
        this.scrollType = 'slow';
        return false;
    },
    mouseout:function(){
        this.scrollType = 'normal';
        return false;
    }
}
ticker1  = new Ticker("scroll","scrollFrame","scrollFrame2",[3,60,0.05,'http://bbs.blueidea.com/rss.php?fid=1']);

/script

/body
/html