xml 有关问题！跪求，

xml 问题！跪求，急啊！
我的xml文件 <?xml version="1.0" encoding="utf-8" ?>
<CommonTypes> //xml文件名ttt.xml
  <Types Name="IDocType">
  <Type ID="01">原件</Type>
  <Type ID="02">复印件</Type>
  <Type ID="03">电子图</Type>
  </Types>
</CommonTypes>


怎样在后台代码 给 DropDownList 负值！
public void DropDownListDateBing()
  {
  ArrayList dropdownlist;
  ...........
  ............
  }

[解决办法]

C# code

     protected void Page_Load(object sender, EventArgs e)    {        if (!IsPostBack)        {            LoadXmlFile();        }            }    public void LoadXmlFile()    {              string path = Server.MapPath("XML/test.xml");  //这里是你文件路径        XmlDocument doc = new XmlDocument();        doc.Load(path);        XmlNodeList nodeList = doc.SelectNodes("CommonTypes/Types/Type");        foreach (XmlNode node in nodeList)        {            ListItem li = new ListItem(node.InnerText,node.Attributes["ID"].Value);            DropDownList1.Items.Add(li);  //DropDownList1是ID        }    }