Cant't get hello world :(

[eluser]hali6sic6[/eluser]
I tried the introduction tutorial but it's giving me errors

Code:

<?php

class Blog extends Controller {

    function index()
    {
        echo 'Hello World!';
    }
}
?>

Is there something wrong here?

[eluser]osci[/eluser]

Code:

class Blog extends CI_Controller {

I suggest you check Upgrading From a Previous Version
starting from 1.7.2 to 2.0 and on since some are outdated.

[eluser]hali6sic6[/eluser]
Ok thanks

[eluser]fivefinger-bd[/eluser]
This is version 2