int i=1;
            XmlDocument xml = new XmlDocument();
            xml.Load(@"E:\a.xml");
            XmlNodeList node = xml.SelectNodes("/structure/Product");
            foreach (XmlNode n in node)
            {
                XmlDocument x = new XmlDocument();
                XmlDeclaration dec = x.CreateXmlDeclaration("1.0", "utf-8", null);
                x.AppendChild(dec);
                XmlNode Product = x.ImportNode(n, true);
                x.AppendChild(Product);
                x.Save(@"E:\" + i + ".xml");
                i++;
            }