How can sessions be managed when including PHP pages via Ajax in a main page?

When including PHP pages via Ajax in a main page, sessions can be managed by starting the session in the main page before any Ajax requests are made. This ensures that the session is initialized and available for use in the included PHP pages. Additionally, you can pass the session ID in the Ajax request headers to maintain the session state across different PHP files.

// main_page.php

session_start();

// Include jQuery library and other necessary scripts

// Make Ajax request to include_php_page.php
```

```php
// include_php_page.php

session_id($_SERVER['HTTP_SESSION_ID']);
session_start();

// Your PHP code here that requires session variables