Simple Create Child Node in XML

 
XmlDocument doc = new XmlDocument();
          doc.Load("PHP_DataAdapter.xml");
          XmlElement _aidRoot = doc.CreateElement("Adapter");
          _aidRoot.InnerXml = @"1234"
              + @""
              + @"";
          doc.DocumentElement.AppendChild(_aidRoot);
          doc.Save("PHP_DataAdapter.xml");