Undefined variable: _SESSION when sending variables via post through JavaScript trigger

Question

In my index.php file I call session_start() and set a couple of session variables. In a second PHP file I would like to access these session variables.

Answer 1

There's nothing special whatsoever about POST requests and sessions.
You just need to call session_start at the top of every file request you want to use sessions in, that's it.

Try again with that in mind, it ought to work.