urgent help needed

[M.Waqas Aslam]

hello !
i am working on a single page of asp ,and i am using ext js 4.0 with it . i have a grid of extjs , my task is to show records in that grid from mssql server 2008 , for getting records i am using webservice . code for webservice is this

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Services;
using System.IO;
using System.Text;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Web;
using System.Web.Script.Services;
using System.Web.Script.Serialization;
using System.Runtime.Serialization;
namespace JSWorking
{
    /// <summary>
    /// Summary description for WebService2
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
    // [System.Web.Script.Services.ScriptService]
    public class WebService2 : System.Web.Services.WebService
    {
        HttpContext postedContext = HttpContext.Current;
        [WebMethod (EnableSession = true )]
        [ScriptMethod (ResponseFormat = ResponseFormat .Json ,UseHttpGet = true ,XmlSerializeString = false )]
        public List <Object[]> GetData ( string Name , int PhoneNo , int CellNo , int IDNo , string Advance )
        {
            string strCN = "Data Source=waqas\\sqlexpress2;Initial Catalog=myDB;User Id=waqas;Password=patanahi;";
            SqlConnection CN = new SqlConnection(strCN);
            CN.Open();
            string strQuery = "Select Name,PhonenO,CellNo,IDNo,Advance from Students";
            SqlCommand cmd = new SqlCommand(strQuery,CN);
            cmd.CommandType = CommandType.Text;
            SqlDataReader reader = cmd.ExecuteReader();
            List<Object[]> myArray = new List<object[]>();
            try
            {
                while (reader.Read())
                {
                    Object[] values = new Object[reader.FieldCount];
                    int fieldCount = reader.GetValues(values);
                    myArray.Add(values);

                }
                return myArray;
            }
            catch (Exception ex)
            {
            throw ex;  

            }
            finally 
            {
            reader.Close ();
                reader.Dispose ();
                cmd.Dispose ();
                CN.Close ();
                CN.Dispose ();
            }
            }
        }
    }

this code is working fine , but the prob is that how can i show all the records in grid , i have no idea about JS and JSON , please help me , how to make data store , and how to get all the data from the webservice .

Please help me in this , any help will be greatly appreciated.

Best Regards