#region 读写xml文件的2个小函数，2005 4 2 by hyc
public void SetXmlFileValue(string xmlPath,string AppKey,string AppValue)//写xmlPath是文件路径+文件名，AppKey是 Key Name，AppValue是Value
{
XmlDocument xDoc = new XmlDocument();
xDoc.Load(xmlPath);
XmlNode xNode;
XmlElement xElem1;
XmlElement xElem2;
xNode =xDoc.SelectSingleNode("//appSettings");
xElem1 = (XmlElement)xNode.SelectSingleNode("//add[@key='" + AppKey + "']");
if ( xElem1 != null )
{
xElem1.SetAttribute("