System Xml C# by API

using System;
using System.Xml;
using System.IO;
using System.Text;
class MainClass {
    private static void Main() {
        FileStream fs = new FileStream("products.xml", FileMode.Create);
        XmlWriter w = XmlWriter.Create(fs);
        w.WriteStartDocument();
        w.WriteStartElement("products");
        w.WriteStartElement("product");
        w.WriteAttributeString("id", "1001");
        w.WriteElementString("productName", "Gourmet Coffee");
        w.WriteElementString("productPrice", "0.99");
        w.WriteEndElement();
        w.WriteStartElement("product");
        w.WriteAttributeString("id", "1002");
        w.WriteElementString("productName", "Blue China Tea Pot");
        w.WriteElementString("productPrice", "102.99");
        w.WriteEndElement();
        w.WriteEndElement();
        w.WriteEndDocument();
        w.Flush();
        fs.Close();
        fs = new FileStream("products.xml", FileMode.Open);
        XmlReader r = XmlReader.Create(fs);
        while (r.Read()) {
            if (r.NodeType == XmlNodeType.Element) {
                Console.WriteLine("<" + r.Name + ">");
                if (r.HasAttributes) {
                    for (int i = 0; i < r.AttributeCount; i++) {
                        Console.WriteLine("\tATTRIBUTE: " +
                          r.GetAttribute(i));
                    }
                }
            } else if (r.NodeType == XmlNodeType.Text) {
                Console.WriteLine("\tVALUE: " + r.Value);
            }
        }
    }
}