function error

[eluser]Unknown[/eluser]
I am just start with codeigniter 1 day ago
and i create a blog page like the user guide told me

<?php
class Blog extends Controller {

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

function com()
{
echo 'Hello World2222222222222!';
}
}
?>

and put the right code on the config file

but only the function index is loading
when i am trying to load the com function its show me the index
i am us this url: http://mydomain.com/blog/com

anyone can help me?

thanks.