Codeigniter 2级URL

I'm working on CI controller, and have problem with achieving URL I want to get.

I want to achieve URL like:

/someclass/url1/$id/url2

    class Someclass extends CI_Controller
    {
    function __construct()
    {
            parent::__construct();

            $this->load->helper('url');
            $this->load->model('classes');
    }

    function index()
    {
       $this->url1($id=null);   
    }

    function url1($Id)
    {
//code  
    }

    function url2() 
    {
//code  
}

}

Also you could use , $this->uri->segment() from the URI class, its easier for me.

I'm writing it maybe somebody will need it.

$total_segments = count ( $this->uri->segment_array() );

if($total_segments=='2'){

// this is something site.com/controllname/products

}
else if($total_segments=='3'){

// this is something site.com/controllname/products/id

}

Such a noob question!

I've added 2nd parameter to the function and that made my answer.

Thanks for help!