jQuery AutoComplete Plugin in ASP.Net and Oracle Database

<%@ WebHandler Language="C#" Class="Search_Auto" %>

using System;
using System.Web;
using System.Data.OracleClient;
using System.Configuration;
using System.Text;

public class Search_Auto : IHttpHandler {
    
    public void ProcessRequest (HttpContext context) {
        string prefixText = context.Request.QueryString["q"];
        using (OracleConnection conn = new OracleConnection())
        {
            conn.ConnectionString = ConfigurationManager
                    .ConnectionStrings["Oracle_Itech"].ConnectionString;
            
            
        //conn = WebConfigurationManager.ConnectionStrings["Oracle_Itech"].ConnectionString;
  
            
            using (OracleCommand cmd = new OracleCommand())
            {
                cmd.CommandText = "select xaccdesc from plmster where " +
                "xaccdesc like @TextBox2 + '%'";
                cmd.Parameters.AddWithValue("@TextBox2", prefixText);
                cmd.Connection = conn;
                StringBuilder sb = new StringBuilder();
                conn.Open();
               
                using (OracleDataReader sdr = cmd.ExecuteReader())
                {
                    while (sdr.Read())
                    {
                        sb.Append(sdr["xaccdesc"])
                            .Append(Environment.NewLine);
                    }
                }
                conn.Close();
                context.Response.Write(sb.ToString());
            }
        }
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }

}
i use this link 
http://www.aspsnippets.com/Articles/Using-jQuery-AutoComplete-Plugin-in-ASP.Net.aspx

error is here
  using (OracleDataReader sdr = cmd.ExecuteReader())