codeigniter login Cannot modify header information

itemprop="text">

I test on my localhost is
working well and now show any error but after upload to the godaddy server. it is
codeigniter version 2.2.6.

this error show in
the login page.

Error Message
1

Message: Cannot modify header
information - headers already sent by (output started at
/home/user/public_html/ngapali/test/application/controllers/admin/user.php:1)

Filename:
libraries/Session.php

Line Number:
433

Error Message 2

Message: Cannot modify header information -
headers already sent by (output started at
/home/user/public_html/ngapali/test/application/controllers/admin/user.php:1)

Filename:
libraries/Session.php

Line Number:
689

Admin Controller of My Controller

class
            Admin_Controller extends MY_Controller{

function
            __construct(){
 parent::__construct();



            $this->load->helper('form');

            $this->load->library('form_validation');

            $this->load->library('session');


            $this->load->model('user_m');
 $this->load->model('roomtype_m');
            
 $this->load->model('room_m');

            $this->load->model('roomcapacity_m');




            //login check
 $exception_uris = array(

            'admin/user/login',
 'admin/user/logout'
 );


            if(in_array(uri_string(), $exception_uris) == FALSE) {

            if($this->user_m->loggedin() == FALSE) {

            redirect('admin/user/login');
 }


            }
}}?>

My
login page /user/login

Controller

class
            User extends Admin_Controller {

function __construct(){

            parent::__construct();

}

public function
            index() {
 $this->data['users'] = $this->user_m->get();

            $this->data['subview'] = 'admin/user/index';


            $this->load->view('admin/_layout_main',$this->data);
}


public
            function login() {
 $dashboard = 'l0gadmin/dashboard';

            $this->user_m->loggedin() == FALSE || redirect($dashboard);


            $rules = $this->user_m->rules;

            $this->form_validation->set_rules($rules);


            if($this->form_validation->run() == TRUE){

            if($this->user_m->login() == TRUE){
 redirect($dashboard);

            }else{
 $this->session->set_flashdata('error','That email/password
            combination does not exist ');

            redirect('admin/user/login','refresh');
 }
 }

            $this->data['subview'] = 'admin/user/login';

            $this->load->view('admin/_layout_modal',$this->data);

}

public
            function logout(){
 $this->user_m->logout();

            redirect('admin/user/login');
}}?>

Model

class
            User_m extends MY_Model {



function
            __construct(){

            parent::__construct();
}



public
            function login(){
 $user = $this->get_by(array(
 'email'=>
            $this->input->post('email'),
 'password' =>
            $this->hash($this->input->post('password')),

            ),TRUE);

 if(count($user)){
 $data = array(

            'name'=> $user->name,

 'email' =>
            $user->email,
 'id'=> $user->id,

            'loggedin'=>TRUE,
 );

            $this->session->set_userdata($data);

            }
}

public function logout(){

            $this->session->sess_destroy();

}
public function
            loggedin(){
 return (bool)
            $this->session->userdata('loggedin');
}


public
            function hash($string){
 return hash('sha512', $string .
            config_item('encryption_key'));
}}?>

View
Page of login

             class="row">
 

 
Admin
            Login

 
 echo
            validation_errors();

 echo form_open('');
 $email =
            array(

 'name' => 'email',
 'class' =>
            'form-control',
 'placeholder' => 'Email Address'


            );
 echo form_input($email) . "
";



            $password = array(
 'name' => 'password',
 'class' =>
            'form-control',
 'placeholder' => 'Password'
 );
 echo
            form_password($password) . "
";

 $submit =
            array(
 'name' => 'submit',
 'class' => 'form-control btn
            btn-primary',

 'value' => 'Login'
 );
 echo
            form_submit($submit);

 echo form_close();


            ?>



            




i
search this problem can be of open and closed tag. I try to add all the page but it
still show error. Why?.