a little problem with extJS & log in form

have user_cotnroller

    class UserController < ApplicationController
    def authenticate
       if request.post?
        #User.new(params[:userform]) will create a new object of User,
retrieve values from the form and store it variable @user.
        @user = User.new(params[:userform])
        #@user = User.find_by_id(params[:id])
            #find records with username,password
        valid_user = User.find(:first,:conditions => ["username = ? and
password = ?",@user.username, @user.password])

            #if statement checks whether valid_user exists or not
        if valid_user
            #creates a session with username
          session[:user_id]=valid_user.username
          #data = { :success => 'true', :msg => "Welcome,
#{params[:username]}!" }
            #redirects the user to our private page.
          redirect_to :action => 'private'
        else
          flash[:notice] = "Invalid User/Password"
          #data = { :failure => 'true', :msg => "Username or Password
wrong!" }
          redirect_to :action=> 'login'
        end
      end
    end

      def login
      end

      def private
      if !session[:user_id]
      redirect_to :action=> 'login'
      end
      end

      def logout
        if session[:user_id]
          reset_session
          redirect_to :action=> 'login'
        end
      end

    end

Have login.js

    var userform = new Ext.form.FormPanel({

        baseCls: 'x-plain',

        labelWidth: 75,
        id: 'userform',
        method: 'POST',

        url:'/user/authenticate',

        defaultType: 'textfield',

        items: [{

            fieldLabel: 'Login',

            name: 'username',

            anchor:'90%' // anchor width by percentage

        } ,{

          fieldLabel: 'Password',

          name: 'password',

      inputType: 'password',

          anchor: '90%' // anchor width by percentage

    }],

    buttons: [{

        text: 'Login',

        handler: function() {

            userform.getForm().submit(

                {

                    method: 'POST',

                    waitMsg:'Submitting...',

                    reset : false,

                    success : function(form, action) {

              Ext.Msg.alert('Bravo', action.result.msg);

                        loginWindow.close();

                    /*var redirect = '/admin/welcome';

                    window.location = redirect;

                    */

                    },

                    failure: function(form, action)
{Ext.Msg.alert('Error', action.result.msg)}

                });

            }

        }]

    });

    var loginWindow = new Ext.Window({

        title: 'Login',

        width: 300,

        height:140,

        closable:false,

        minWidth: 300,

        minHeight: 140,

        layout: 'fit',
        id: 'userform',

        plain:true,

        modal:true,

        bodyStyle:'padding:5px;',

        items: userform

    });

    Ext.onReady(function(){

        loginWindow.show(this);

    });

login page

    <script type="text/javascript" src="/ext/adapter/ext/ext-
base.js"></script>
    <script type="text/javascript" src="/ext/ext-all.js"></script>
    <script type="text/javascript" src="/javascripts/login.js"></

    <link rel="stylesheet" type="text/css" href="/ext/resources/css/
ext-all.css" />

    <% if flash[:notice] %>
    <div style="font-family:'Trebuchet MS'; color:#FF0000; font-size:
14px;">
    <%= flash[:notice] %>
    </div>
    <% end %>

    <!--creates form, exectues the authenticate method when the submit
button is clicked-->
    <%= form_tag :action=>'authenticate' %>
    User name:
    <%= text_field("userform", "username",:size=>"20" ) %>
    Password:
    <%= password_field("userform", "password",:size=>"20" )
    %>
    <input type="submit" value=" LOGIN " />

SO, question is.

Without extJS (login,js) everything looks nice. Sessions works and so
on. But i want make form in extJs, i made it, but when i put my right
data (user:test,pw:test) i get in console:

    Processing UserController#authenticate (for 127.0.0.1 at
2011-04-14 13:21:19) [POST]
      Parameters: {"username"=>"test", "password"=>"test"}
      User Columns (0.5ms) SHOW FIELDS FROM `users`
      User Load (0.2ms) SELECT * FROM `users` WHERE (username = NULL
and password = NULL) LIMIT 1

My form doesn't look my data:(

Without extJS (login,js) everything looks nice. Sessions works and so
on. But i want make form in extJs, i made it, but when i put my right
data (user:test,pw:test) i get in console:

   Processing UserController#authenticate (for 127.0.0.1 at
2011-04-14 13:21:19) [POST]
     Parameters: {"username"=>"test", "password"=>"test"}
     User Columns (0.5ms) SHOW FIELDS FROM `users`
     User Load (0.2ms) SELECT * FROM `users` WHERE (username = NULL
and password = NULL) LIMIT 1

My form doesn't look my data:(

Not at all familiar with extjs, but given that you are expecting params[:userform] to contain your data, rails is expecting the names of the inputs to be userform[username] and userform[password], which doesn't seem to tally with what's in your js files.

Fred