[help] Php Session Problem

[Rekcuf]

why do I get this error:

Warning: Unknown(): Your script possibly relies on a session side-effect which existed until PHP 4.2.3. Please be advised that the session extension does not consider global variables as a source of data, unless register_globals is enabled. You can disable this functionality and this warning by setting session.bug_compat_42 or session.bug_compat_warn to off, respectively. in Unknown on line 0

my code:

session_start();
if (!session_is_registered("asdf")) {
	session_unset();
	$userId = 0;
	$userName = "guest";
	$threadPermissions = 0;
	session_register("userId", "userName", "threadPermissions");
}

Waiting for your help..
Thanks very much.

[benson]

I always use sessions like this:

//too begin an session.
session_start();
//too register an var.
$_SESSION['varnam']="Varvalue";
//too check if not empty or something else
if ($_SESSION['varname'] != "")
{
etc.