unable to create session cookie

[eluser]basty_dread[/eluser]
I have downloaded a new copy of Codeigniter 1.7.2
and uploaded it to my testing server
everything is configured then i tried this piece of code

Code:

function Welcome(){
        parent::Controller();    
        $this->load->library('session');
        $this->load->helper('url');
    }
    
    function index(){
        $data['user'] = "testing";
        $this->session->set_userdata($data);
        redirect('welcome/check');
    }
    function check(){
        echo $this->session->userdata('user');
    }

this should output "testing" when i run this code.
but nothing happens.

i am using google chrome browser v.5.0.375.127