Change an Attribute's Value in CSharp

using System;/*from   w w w.  ja  va2  s .  c o  m*/
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Linq;
public class MainClass {
    public static void Main() {
        XElement firstParticipant;
        XDocument xDocument  = new XDocument(
          new XElement("Books", firstParticipant =
            new XElement("Book",
              new XAttribute("type", "Author"),
              new XAttribute("experience", "first-time"),
              new XElement("FirstName", "J"),
              new XElement("LastName", "R"))));

        Console.WriteLine(xDocument);
        firstParticipant.Attribute("experience").Value = "beginner";
        Console.WriteLine(xDocument);
    }
}