Hi, I've searched the web but haven't been able to find a solution to the following challenge: I'd like to somehow associate a function that executes when session_start is called independent of the page session_start is called in. The function is intended to restore constants I've stored in $_SESSION using get_defined_constants() so that they're available again to any PHP page. This seems so straightforward to me but I'm pretty sure the PHP Session extension doesn't support the registration of user-defined events. I was wondering if anyone might have insight into this issue so I can either figure out the solution or stop trying. Ideally, I'd like to just register the function at run-time like so: $constants = get_defined_constants(); $_SESSION["constants"] = $constants["user"]; function event_handler () { foreach ($_SESSION["constants"] as $key => $value) { define($key, $value); } } register_handler("session_start", "event_handler"); So in any webpage, I could just go: session_start(); and all my constants would be available again. Any help would be greatly appreciated.