Xml in C#

gistfile1.cs

// http://msdn.microsoft.com/en-us/library/azsy1tw2.aspx

using System;
using System.IO;
using System.Xml;

public class Sample
{
    public static void Main()
    {
        // Create the XmlDocument.
        XmlDocument doc = new XmlDocument();
        doc.LoadXml("input.xml");

        // Save the document to a file.
        doc.Save("data.xml");
    }
}

// http://msdn.microsoft.com/en-us/library/d271ytdx.aspx

// Load the document and set the root element.
XmlDocument doc = new XmlDocument();
doc.Load("bookstore.xml");
XmlNode root = doc.DocumentElement;

// Add the namespace.
XmlNamespaceManager nsmgr = new XmlNamespaceManager(doc.NameTable);
nsmgr.AddNamespace("bk", "urn:newbooks-schema");

// Select all nodes where the book price is greater than 10.00.
XmlNodeList nodeList = root.SelectNodes(
     "descendant::bk:book[bk:price>10.00]", nsmgr);
foreach (XmlNode book in nodeList)
{
     // Discount prices by 10%.
     double price;
     price = Math.Round(Convert.ToSingle(
          book.LastChild.InnerText) * 0.9, 2);
     book.LastChild.InnerText = price.ToString();
}

// Display the updated document.
doc.Save(Console.Out);