weird bug in my app

[eluser]Iwasignited[/eluser]
Hi all
Here is the code, please let me know what im doing wrong

controller:

Code:

function add_comment($entryID)
    {
        $is_logged_in = $this->is_logged_in();
        $user_id = $this->user_id();
        $this->load->model('entry_model');
        // If the user is not logged in yet, redirect him and send a message
        if(!isset($is_logged_in) || $is_logged_in != true)
        {
            $this->session->set_flashdata('msg', 'You have to login to add comment');
            redirect('site/index');    
            
        }        
        // A not real entry
        if (!$this->entry_model->getDetails($entryID))
        {
                $this->session->set_flashdata('msg', 'Not real entry');
                redirect('site/index');
        }
        // If ok, show the add comment page
        $data['main_content'] = 'add_comment';
        $data['user_id'] = $user_id;
        $data['entry_id'] = $entryID;
        $this->load->view('includes/template', $data);
    }

I receive this error when going to a not real entry

A PHP Error was encountered

Severity: Warning

Message: Cannot modify header information - headers already sent by (output started at C:\AppServ\www\CMS\application\models\entry_model.php:190)

Filename: libraries/Session.php

Line Number: 662
A PHP Error was encountered

Severity: Warning

Message: Cannot modify header information - headers already sent by (output started at C:\AppServ\www\CMS\application\models\entry_model.php:190)

Filename: helpers/url_helper.php

Line Number: 541

Please help me