Sessions are stored server-side, so you cannot add values ​​to them from JavaScript. All you get on the client side is the session cookie containing the id. One possibility is to send an AJAX request to a server-side script, which will set session variables. jQuery’s .post() method example:

$.post('/setsessionvariable.php', { name: 'value' });

Of course, you should be careful about exposing such scripts.

In JavaScript:

jQuery('#div_session_write').load('session_write.php?session_name=new_value');

In the session_write.php file:

session_start();

if (isset($_GET['session_name'])) {$_SESSION['session_name'] = $_GET['session_name'];}
?>

In HTML: