I am new in Extjs 4.0. I am unable to retrieve data from server side. I have an asp.net MVC application. I am not clear about root. Suppose want to populate a grid. Here is my code..

var itemsPerPage = 2; // set the number of items you want per page

var storee = Ext.create('Ext.data.Store', {
id: 'simpsonsStore',
autoLoad: false,
fields: ['CompanyId', 'CompanyName', 'Address', 'Phone', 'Fax', 'Email', 'SLogoPath', 'MLogoPath', 'PrimaryContact'],
pageSize: itemsPerPage, // items per page
proxy: {
type: 'ajax',
url: './SelectCompany', // url that will load data with respect to start and limit params
reader: {
type: 'json',
root: 'Data',// I am not clear about root. what is root????
totalProperty: 'total'

url: './SelectCompany', work fine and server side have no problem.
root: '',// I am not clear about root. what is root????
When i run my program, only show empty grid panel with pagging toolbar.
How can i solve my problem.
Please help me.


// specify segment of data you want to load using params
params: {
start: 0,
limit: itemsPerPage

Ext.create('Ext.grid.Panel', {
title: 'Simpsons',
store: storee,
columns: [
{ header: 'Name', dataIndex: 'CompanyName' },
{ header: 'Email', dataIndex: 'Email' },
{ header: 'Phone', dataIndex: 'Phone' }
width: 400,
height: 125,
dockedItems: [{
xtype: 'pagingtoolbar',
store: storee, // same store GridPanel is using
dock: 'bottom',
displayInfo: true
// renderTo: Ext.getBody()
renderTo: 'content'