Using AJAX with ASP.NET 2.0

using System;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Xml;
using System.Xml.Xsl;
using System.Xml.XPath;

public partial class Names : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (Request.QueryString["q"] != null)
        {
            GetNames();
        }
    }
    
    private void GetNames()
    {
        string strQuery = Request.QueryString["q"];

        //Create the XML-like string to be sent back to the request 
        string strXmlNames = "";

        ArrayList al = new ArrayList();
        al = RetreiveNames();

        // Copies the elements of the ArrayList to a string array.
        String[] arrStrNames = (String[])al.ToArray(typeof(string));

        foreach (string strName in arrStrNames)
        {
            strXmlNames += "<user><name>" + strName + "</name></user>";
        }
        strXmlNames = "<users>" + strXmlNames + "</users>";

        //Create an XmlDocument object to store the XML string that we created 
        XmlDocument xDoc = new XmlDocument();
        xDoc.LoadXml(strXmlNames);

        //Create a navigator object to use in the XSL transformation 
        XPathNavigator xPathNav = xDoc.CreateNavigator();

        //Create the XSLTransform object 
        XslCompiledTransform xslt = new XslCompiledTransform();
        xslt.Load(Server.MapPath("Names.xslt"));

        //Do the transformation and send the results out to the Response object's output stream 
        xslt.Transform(xPathNav, null, Response.OutputStream);
        
    }

    public ArrayList RetreiveNames()
    {
        ArrayList al = new ArrayList();

        SqlConnection con = new SqlConnection();
        con.ConnectionString = "Data Source=.;Integrated Security=True;Database=Northwind";

        SqlCommand cmd = new SqlCommand("SELECT ContactName from Customers WHERE ContactName LIKE UPPER('" + Request.QueryString["q"] + "%')", con);
        
        con.Open();

        SqlDataReader rdr = cmd.ExecuteReader();

        while (rdr.Read())
        {
            al.Add(rdr[0].ToString());
        }
        return al;
    }
}