public class Item
    {
        private string code;
        public string Code
        {
            get { return code; }
            set { code = value; }
        }
        public Item()
        {
        }
        public Item( string filename )
        {
            XmlDocument doc = new XmlDocument();
            doc.Load(filename);
            code = doc.SelectSingleNode("/item/code").InnerText;
        }
        public void Save( string filename )
        {
            XmlDocument doc = new XmlDocument();
            XmlElement itemElement = doc.CreateElement("item");
            doc.AppendChild(itemElement);
            XmlElement codeElement = doc.CreateElement("code");
            itemElement.AppendChild(codeElement);
            codeElement.InnerText = code;
            doc.Save(filename);
        }
    }