asp.net+XML "修改模块"代码修改,该如何解决

using System;using System.Data;using System.Configuration;using System.Collections;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.Xml;using System.IO;public partial class manager_edit_news : System.Web.UI.Page{    protected void Page_Load(object sender, EventArgs e)    {        string url = Server.MapPath("../../news.xml");        string news_id = Request.QueryString["news_id"];        XmlDocument xmlDoc = new XmlDocument();        xmlDoc.Load(url); //加载XML文档        XmlNode root = xmlDoc.SelectSingleNode("news/content[news_id ='" + news_id + "']");        if (root != null)        {            Title.Text = root.ChildNodes[0].InnerText;            Date.Text = DateTime.Now.ToString();            Description.Text = root.ChildNodes[2].InnerText;            Content.Value = root.ChildNodes[3].InnerText;        }    }    protected void btnSend_Click(object sender, EventArgs e)    {        string url = Server.MapPath("../../news.xml");        string news_id = Request.QueryString["news_id"];        string title = Request.Form["title"];        string description = Request.Form["description"];        string content = Request.Form["Content"];        //获取行信息的索引字段news_id        XmlDocument xmlDoc = new XmlDocument();        xmlDoc.Load(url); //加载XML文件        XmlNode root = xmlDoc.SelectSingleNode("news");//查找news节点        XmlNodeList xnl = root.ChildNodes; //获取news下面所以子节点        for (int i = 0; i < xnl.Count; i++)        {            XmlNodeList xnl11 = xnl.Item(i).SelectNodes("news_id");//查找news_id下面节点集合            XmlElement xe = (XmlElement)xnl11.Item(0); //news_id节点下面的元素            if (xe.InnerText == news_id) //获取节点以及所有子集的串联值            {                xe.InnerText = news_id;                xe.ParentNode.ChildNodes.Item(0).InnerText = title;                xe.ParentNode.ChildNodes.Item(1).InnerText = DateTime.Now.ToString();                xe.ParentNode.ChildNodes.Item(2).InnerText = description;                [color=#FF0000]xe.ParentNode.ChildNodes.Item(3).InnerText = content;[/color]            }        }        xmlDoc.Save(url);        Response.Redirect("manager.aspx");    }}

<news originalMenuTitleColor="0xCCCC33" originalMenuDateColor="0x666666" currentMenuTitleColor="0x00CCFF" currentMenuDateColor="0xCCCCCC" arrowOutColor="0x999999" arrowOverColor="0xCCCC33" mainTitleColor="0xCCCC33" menuSpacing="40" textHolderXStart="220" textHolderXFinish="240" mainTextWidth="600" scrollbarX="855">  <content>    <title>测试文章</title>    <date>2008-12-22 12:27:37</date>    <description>测试文章简介</description>    <main>&amp;lt;p&amp;gt;111&amp;lt;/p&amp;gt;</main>    <news_id>1</news_id>  </content>