session_register() with mysql_insert_id()

[edh]

After querying a database, I am trying to register the the mysql_instert_id() variable from the database into the session.

However when registering the session, the session only contains the following:

!user_id|

The session should say:

user_id|i:1;

Or something like that. The user_id IS being assigned because I can echo it's value to the screen just fine.

Here is my code:

$result = mysql_query($query);
$user_id = mysql_insert_id();
session_start();
session_register('user_id');

Any hints?

Ed

[edh]

Found the problem.

I was actually doing the session_register() inside a function. According to the manual the registered value must be a global variable; here is the code that works.

function submit() {

$result = mysql_query($query);
global $user_id;
$user_id = mysql_insert_id();
session_start();
session_register('user_id');

}