define( '_JEXEC', 1 );
define( 'JPATH_BASE', realpath(dirname(__FILE__).'/' ));
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();
$session->set('continent',123456); //Set session name and value
echo $session->get('continent'); //Get session value

$session =& JFactory::getSession();
echo $session->get('continent');