Use value in index method in Codeigniter

Use value in index method in Codeigniter

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Category extends CI_Controller {
    public function index($param)
    {
        echo $param;
        $this->load->view('category_

message');
    }
    public function _remap($param) {
        $this->index($param);
    }
}

use is as:
http://localhost:90/CodeIgniter_2.1.4/category/laptop