prototype 学习

   这段时间不是很忙的,终于有机会学习一下javascript,这块一直是我的弱项,得找个机会补习一下啊,
   通过两天的学习,有了个大体的认识,
   学习过程中可以参考 http://591wap.cn/works/prototype/index.html 
   对大家学习应该有帮助的,

          <input type="hidden" id="hidxml" runat="server" />  //xml 文件的地址
          <input type="button" value="GetHtml" onclick="GetXml()" />
          <div id="placeholder"></div>
           <textarea id="result" cols='60' rows='10' ></textarea> 
   <?xml version="1.0" encoding="utf-8"?>
<Books>
      <Book>
            <Name>HTML Book</Name>
            <Author>Lee</Author>
      </Book>
      <Book>
            <Name>XML Book</Name>
            <Author>liu</Author>
      </Book>
</Books>
       function showBooks(originalRequest)  //本来打算把返回的xml流转化为html 的table 的格式
    { 
               var results = originalRequest.responseXML;
                var table = document.createElement("table");        
                var books = results.getElementsByTagName("Book");        
                 alert(books.length);            //    ---总是0           
                for(var i = 0; i < books.length; i++) {
                    book = books[i];
                    var name = book.getElementsByTagName("Name")[0].firstChild.nodeValue;
                    var author = book.getElementsByTagName("Author")[0].firstChild.nodeValue;
                    var row = document.createElement("tr");
                    var cellname=document.createElement("td");
                    var cellauthor=document.createElement("td");
                    cellname.innerText = name;
                    cellauthor.innerText=author;
                   
                    row.appendChild(cellname);
                    row.appendChild(cellauthor);
                    table.appendChild(row);
                }
           
                var con=$("placeholder");

                con.innerHTML = table.outerHTML;

    }
    function GetXml()
     {
         var url = './GetXml.ashx';
               var pars = 'file='+$F("hidxml");

               var myAjax = new Ajax.Request(
                    url,
                    {method: 'get', parameters: pars, onComplete: showBooks}
                    );
//         var myAjax = new Ajax.Updater({success: 'placeholder'},url,{method: 'get',parameters: pars,onFailure: reportError});

         }
         function reportError()
           {
            alert('ERROR');
           }
           function Suecss()
            {
             alert(" over");
            }
./GetXml.ashx 是为了生成xml文件的,具体如下
[WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class GetXml : IHttpHandler {

        public void ProcessRequest(HttpContext context) {
         string fileName =   context.Request.QueryString["file"];
            context.Response.ContentType = "text/plain";
            context.Response.Write(CreateXmlDocument(fileName));
        }

        public bool IsReusable {
            get {
                return false;
            }
        }
        private string CreateXmlDocument(string file) {

            string Result = string.Empty;
            XmlTextWriter writer = new XmlTextWriter(file, System.Text.Encoding.UTF8);
            writer.Formatting = Formatting.Indented;
            writer.Indentation = 6;
            writer.WriteStartDocument();
            writer.WriteStartElement("Books");
            GenerateClassXmlNode(writer);
            writer.WriteEndElement();
             writer.WriteEndDocument();
            writer.Close();
            XmlDocument xdoc = new XmlDocument();
            xdoc.Load(file);
            return xdoc.OuterXml;
        }
        private  void GenerateClassXmlNode(XmlTextWriter writer) {
            writer.WriteStartElement("Book");
            writer.WriteElementString("Name", "HTML Book");
            writer.WriteElementString("Author", "Lee");
            writer.WriteEndElement();

            writer.WriteStartElement("Book");
            writer.WriteElementString("Name", "XML Book");
            writer.WriteElementString("Author", "liu");
            writer.WriteEndElement();
        }
   那位高手能解答一下啊,谢谢拉