session_register or $_SESSION

I am using PHP 4.3 (the latest php)

i have heard that we should use $_SESSION rather than session_register to register a session...is it true?

also I should no longer use session_is_registered() or anything alike....i should use isset($_SESSION()) instead....

can anyone give comments about the usage of session in PHP4.3 or the latest version...

AND, a big problem, i ran the following code and it is not working until i refresh it for few or more times...it said that DNS error and server is not found...why's that?

<?php
session_start();

$fromPage = "/kenny/item_details.php";

if (isset($_SESSION['userid'])){

?>
okay , YOU ARE LOGGED IN !!!
<a href="/kenny/TestSession/logout.php"> LOGOUT </a>
<?
} else {
?>
Not okay, You are not logged in !!!
<? } ?>

I would recomend using $_SESSION[] just for ease of use..

and if you do use $_SESSION[] you are right, you will need to use isset($_SESSION[])

Not sure why that code isnt working, unless you're not setting $_SESSION['userid'] = something in another part of the code.. as long as you're setting $_SESSION['userid'] to a value then it should work..