New to CodeIgniter

[eluser]davy_yg[/eluser]
Hello,

I am new to codeigniter, I am following code igniter tutorial:

Introduction:
Static Pages

Where should I add this codes:

public function view($page = 'home')
{

if ( ! file_exists('application/views/pages/'.$page.'.php'))
{
// Whoops, we don't have a page for that!
show_404();
}

$data['title'] = ucfirst($page); // Capitalize the first letter

$this->load->view('templates/header', $data);
$this->load->view('pages/'.$page, $data);
$this->load->view('templates/footer', $data);

}

I don't really understand the instruction.