Ajax request problem

Question

Hi , I am writting a simple login application using Ext-js and servlet.
I need , show login form , if ok then go to success page , with some list generated at server sider otherwise to error page.
Using Ext.FormPanel , I am submitting form and request param using Ajax request.
Problem is , I am able to submit a request , it is hitting to doPost() method of servlet , but when it comes back not redirected to any erropage or success page.
following is the code of login.js, servlet and jsp . Please help me out.I am using Ext.js 3
login.js
Ext.ns('ediscovery');
Ext.onReady(function() {
    var loginForm = Ext.extend(Ext.FormPanel, {
        id : 'loginForm',
        initComponent : function() {
            //this.standardSubmit = true
            this.title = 'Please login'
            //this.url = '/MainController'
            this.items = this.getPageItems();
            this.padding = 30
            this.buttons = this.getButtons();
            this.bodyBorder = false
            this.labelAlign = 'right'
                this.width = 350
            this.style = { marginLeft : '850px',marginRight:'50px',marginTop:'100px'}  
            loginForm.superclass.initComponent.call(this);
        getPageItems : function() {
            var items = [];
            var userNameField = new Ext.form.TextField({
                name : 'userName',
                id : 'userName',
                fieldLabel : 'User Name'
                //,anchor : '60% 6%'
                ,allowBlank : false  
                ,blankText : 'This field is required'
                ,value:'eediscoverycloud'
            var passwordField = new Ext.form.TextField({
                name : 'testname',
                fieldLabel : 'Password',
                id : 'password',
                inputType : 'password'
                //,anchor : '60% 6%'
                ,allowBlank : false  
                ,blankText : 'This field is required'
                ,value:'parse@123'
            items.push(userNameField);
            items.push(passwordField);
            return items;
        ,getButtons : function(){
            var buttons = [];
            var submitBtn = new Ext.Button({
                text : 'Submit'
                ,handler : function(){
                    var userName = Ext.getCmp('userName').getValue();
                    var password = Ext.getCmp('password').getValue();
                    console.log("User Name : "+userName);
                    console.log("Password : "+password);
                    var cmp = Ext.getCmp('loginForm');
                    //cmp.getEl().mask("Processing");
                    /*var fp = this.ownerCt.ownerCt;
                    fp.getForm().submit();*/
                    Ext.Ajax.request({
                        url:"MainController"
                        ,method : 'post'
                        ,params : "userName="+userName+"&password="+password
                        /*,success : function(response,option){
                            console.log(response);
                            Ext.Msg.alert('Status', 'Orders Saved successfully.');
                            cmp.getEl().unmask();
                        ,failure : function(response,option){
                            console.log(response);
                            Ext.Msg.alert('Status', 'Some error occured. Please contact to Administrator');
                            cmp.getEl().unmask();
            var resetBtn = new Ext.Button({
                text : 'Reset'
            buttons.push(submitBtn);
            buttons.push(resetBtn);
            return buttons;
    new Ext.Viewport({
        resizable: false
        ,items : [new loginForm()]
servlet
package com.ediscoverycloud.controller;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.ediscoverycloud.util.DocWriter;
import com.ediscoverycloud.util.Order;
import com.ediscoverycloud.util.ReadMail;
* Servlet implementation class MainController
public class MainController extends HttpServlet {
    private static final long serialVersionUID = 1L;
     * @see HttpServlet#HttpServlet()
    public MainController() {
        super();
        // TODO Auto-generated constructor stub
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String userName = request.getParameter("userName");
        String password = request.getParameter("password");
        request.getRequestDispatcher("/error").forward(request, response);
        System.out.println("Done");
Web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>eDiscoveryCloudWeb</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <description></description>
    <display-name>MainController</display-name>
    <servlet-name>MainController</servlet-name>
    <servlet-class>com.ediscoverycloud.controller.MainController</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>MainController</servlet-name>
    <url-pattern>/MainController</url-pattern>
  </servlet-mapping>
<servlet>
      <servlet-name>Error Page</servlet-name>
      <jsp-file>/errorPage.jsp</jsp-file>
  </servlet>
  <servlet-mapping>
      <servlet-name>Error Page</servlet-name>
      <url-pattern>/error</url-pattern>
  </servlet-mapping>
</web-app>

Answer 1

if u want to move from pages like from jsp to servlet and html page
to another one u have to use ther response.redirection there.
from this u can move arround the pages.