今晚打老虎

            XmlDocument doc = new XmlDocument();
            doc.Load(webDiskPath + "Web.Config");
            XmlNamespaceManager nsmgr = new XmlNamespaceManager(doc.NameTable);
            nsmgr.AddNamespace("ab", "http://schemas.microsoft.com/.NetConfiguration/v2.0");
            XmlNode xn = doc.SelectSingleNode("//ab:configuration/ab:system.web/ab:authorization",nsmgr);
            XmlElement xe = doc.CreateElement("","allow","http://schemas.microsoft.com/.NetConfiguration/v2.0");
            xe.SetAttribute("users", theUserName);
            xn.AppendChild(xe);

            xe = doc.CreateElement("", "deny", "http://schemas.microsoft.com/.NetConfiguration/v2.0");
            xe.SetAttribute("users", "*");
            xn.AppendChild(xe);

            doc.Save(userWebDiskPath + "\\Web.Config");