User name required in PHP Script

[zeeshanhashmi]

Hi

I have a PHP script and that script is attached to Joomla, using Wrapper Iframe.

I want to get the current loggedin user's username. But I cant find a solution.

I tried :

global $my ;
$my->username;

but it has nothing if I echo it. I tried Jfactory, but it shows Fatal Error that Class JFactory is not found.
I tried to add the references to defines.php and framework.php, but even that doen;t helped me. My script is residing in a folder under public_html.

Please help as I am very very depressed !