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", "Tea Pot");
        w.WriteElementString("productPrice", "12.99");
        w.WriteEndElement();
        w.WriteEndElement();
        w.WriteEndDocument();
        w.Flush();
        fs.Close();
    }
}