How to access session variables set by an external script in joomla site

How to access session variables set by an external script ??

Situation: when you call a session variable in Joomla from an external script, it appears to be empty.

Solution: Replace session_start(); in your external script with 
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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();

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Be sure to change JPATH_BASE to suit your directory structure.
Replace the $_SESSION[ 'name' ] = "value"; in your external script with 
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$session =& JFactory::getSession();

$session->set('name', "value");

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Now you can retrieve this session variable using:

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$session =& JFactory::getSession();

echo $session->get('name');

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