I have a xml file and an xslt file in my website project.

xml file:

```
<root>
  <employee>
    <firstname>Kaushal</firstname>
    <lastname>Parik</lastname>
  </employee>
  <employee>
    <firstname>Abhishek</firstname>
    <lastname>Swarnkar</lastname>
  </employee>
</root>

```

xslt:

```
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl" xmlns:Concat="urn:XslSample">
  <xsl:output method="html" indent="yes"/>
  <xsl:template match="root">
      <xsl:for-each select="employee">
        <![CDATA[Concatenated name is ]]>
            <xsl:value-of select="Concat:GetFullName(firstname,lastname)"/>
            <xsl:value-of select="age"/>
        <br />
        </xsl:for-each>
    </xsl:template>
</xsl:stylesheet>

```

aspx.cs:

```
using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Xml.XPath;
using System.Xml.Xsl;
using System.Xml;
using System.IO;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        try
        {
            MemoryStream objStream = new MemoryStream();
            StreamWriter objWriter = new StreamWriter(objStream, System.Text.Encoding.UTF8);

            XPathDocument doc = new XPathDocument(Server.MapPath("XMLFile.xml"));
            XslCompiledTransform trans = new XslCompiledTransform();
            trans.Load(Server.MapPath("XSLTFile.xslt"));

            //create the XslArgumentList and new BookUtils object
            XsltArgumentList argList = new XsltArgumentList();

            Concat objUtil = new Concat();

            //this tells the argumentlist about BookUtils
            argList.AddExtensionObject("urn:XslSample", objUtil);

            //new XPathNavigator
            XPathNavigator nav = doc.CreateNavigator();

            //do the transform
            trans.Transform(nav, argList, objWriter);
            //objWriter.Flush();
            objStream.Position = 0;
            StreamReader oReader = new StreamReader(objStream);
            string strResult = oReader.ReadToEnd();
            //objWriter.Close();
            //oReader.Close();
            Response.Write(strResult);
        }
        catch (Exception Ex)
        { Response.Write(Ex.Message); }
    }
}

public class Concat
{
    public Concat()
    { }

    public string GetFullName(string firstname, string lastname)
    { return "Mr." + firstname; }
}

```

When I run the site, I need to call a c# function from xslt and alter the values in xml file.... I am adding a text (say "Mr.") in front of every firstname through a c# code.... After adding, it writes the output as a response, but the original xml is not modified. I want that to be reflected in the xml file....

xml output needed:

```
<root>
  <employee>
    <firstname>Mr.Kaushal</firstname>
    <lastname>Parik</lastname>
  </employee>
  <employee>
    <firstname>Mr.Abhishek</firstname>
    <lastname>Swarnkar</lastname>
  </employee>
</root>

```

Also, as a next step, I need to add another node in the xml file (say age) through another c# function.... Please note that the c# function should be called from my xslt file.... Can anyone help me with a simple code for this????

Final xml required:

```
<root>
  <employee>
    <firstname>Mr.Kaushal</firstname>
    <lastname>Parik</lastname>
    <age>34</age>
  </employee>
  <employee>
    <firstname>Mr.Abhishek</firstname>
    <lastname>Swarnkar</lastname>
    <age>30</age>
  </employee>
</root>

```