error next pagination

[eluser]zacksyah[/eluser]
i've error for page two pagination. This below link of pagination
http://localhost/ci/index.php/controller...iewnosql/5
this is code from apps

Code:

<?php

class Controller_nosql extends CI_Controller {

    function __construct() {
        parent::__construct();
        $this->load->library('session');
        $this->load->model('model_nosql','bps');
        $this->load->library('pagination');
        $this->load->library('Mongo');
    }

    function index($offset='') {
        $per_page = 5;
        $config['base_url'] = site_url(). '/controller_nosql/viewnosql';
        $total = $this->bps->count();
        //$query = "{"."'province_id':'94'"."},{"."province_id:1"."}";
        $data['bps'] = $this->bps->all_pagination($per_page, $offset);

        $config['per_page'] = $per_page;
        $config['total_rows'] = $total;
        $config['uri_segment'] = 3;
        //$config['base_url'] = $base_url;

        $this->pagination->initialize($config);

        $data['create_links'] = $this->pagination->create_links();

        $this->load->view('viewnosql', $data);
    }
    
    function cari($offset=''){
        $this->load->library('pagination');
        $total = 0;
        $per_page = 5;
        $config['base_url'] = site_url() . '/controller_nosql/cari';
        
        $data['bps'] = $this->bps->search();
        $config['per_page'] = $per_page;
        $config['total_rows'] = $total;
        $config['uri_segment'] = 3;
        $this->pagination->initialize($config);

        $data['create_links'] = $this->pagination->create_links();

        $this->load->view('viewnosql', $data);
        
        
    }
}

?>

Code:

<?php

class Model_nosql extends CI_Model {

    function __contruct() {
        parent::__construct();
        $this->connection = new Mongo('localhost:27017');
    }

    function MongoAll() {
        $lihat = array();
        $lihat = $this->mongo->db->bps->find();
        return $lihat;
    }

    function all_dropdown() {
        $lihat = array();
        $query = $this->mongo->db->bps->find(array(), array('_id' > 1, 'nama' => 1));

        foreach ($query as $row) {
            $query[(string) $row['_id']] = $row['province_id'];
        }
        return $query;
    }

    function update($_id) {
        $author = array(
            'province_id' => $this->input->post('province_id'),
            'nama_propinsi' => $this->input->post('nama_propinsi'),
            'regency_id' => $this->input->post('regency_id'),
            'regency_name' => $this->input->post('regency_name'),
            'sub-district_id' => $this->input->post('sub-district_id'),
            'sub-district_name' => $this->input->post('sub-district_name'),
            'village_id' => $this->input->post('village_id'),
            'village_name' => $this->input->post('village_name'),
            'NBS' => $this->input->post('NBS'),
            'NSBS' => $this->input->post('NSBS'),
            'NUS' => $this->input->post('NUS'),
            'NUP' => $this->input->post('NUP'),
            'sample_type' => $this->input->post('sample_type'),
            'sample_name' => $this->input->post('sample_name'),
            'name' => $this->input->post('name'),
            'address' => $this->input->post('address'),
            'RT' => $this->input->post('RT'),
            'RW' => $this->input->post('RW'),
            'zip_code' => $this->input->post('zip_code'),
            'phone' => $this->input->post('phone'),
            'EXT' => $this->input->post('EXT'),
            'FAX' => $this->input->post('FAX'),
            'EMAIL' => $this->input->post('EMAIL'),
            'phone' => $this->input->post('HOMEPAGE'),
            'activity' => $this->input->post('activity'),
            'category_code' => $this->input->post('category_code'),
            'category_name' => $this->input->post('category_name'),
            'kbli_code' => $this->input->post('kbli_code'),
            'label' => $this->input->post('label'),
            'business_name' => $this->input->post('business_name'),
        );
        $criteria = array('_id' => new MongoID($_id));
        $this->mongo->db->bps->update($criteria, array('$set' => $author));
    }

    function all_pagination($limit, $offset) {
        $authors = array();
        if ($offset) {
            $authors = $this->mongo->db->bps->find()->limit($limit)->skip($offset)->sort(array('_id' => -1));
        } else {
            $authors = $this->mongo->db->bps->find()->limit($limit)->sort(array('_id' => -1));
        }
        return $authors;
    }

    function find_by_id($_id) {
        $author = array();
        $author = $this->mongo->db->bps->findOne(array('_id' => new MongoID($_id)));
        return $author;
    }

    function count() {
        $total = $this->mongo->db->bps->count();
        return $total;
    }

    function search() {
        $c = $this->input->POST('cari');
        return $this->mongo->db->bps->find(array('business_name' => $c));
        
    }

}

?>

what's wrong with the apps code? please help me, thanks in advance