Access joomla session from external pages

define( '_JEXEC', 1 );

define('JPATH_BASE', dirname(__FILE__) );//this is when we are in the root

define( 'DS', DIRECTORY_SEPARATOR );

require_once ( JPATH_BASE .DS.'includes'.DS.'defines.php' );

require_once ( JPATH_BASE .DS.'includes'.DS.'framework.php' );

$mainframe =& JFactory::getApplication('site');

$mainframe->initialise();

$session =& JFactory::getSession();

$myUser = $session->get( 'myUser', 'empty' );