Question

This statement works fine if I only use it once, but not when I need to use it several times. I’m curious as to why, but more importantly I would like to know how I can get around that.

<?php if (isset($_SESSION['SESS_USER_ID'])) { ?>         
<?php }  
else {?>
<?php } 

I need to change several items on the page depending upon whether or not the user is logged in (menu items, messages to the user, etc.)

Answer 1

Quick way around it would be:

<?php $logged_in = (isset($_SESSION['SESS_USER_ID'])); ?>

then

<?php if ($logged_in) : ?>
   //show secret stuff
<?php else : ?>
   // show public stuff
<?php endif; ?>

BUT

There is something wrong going on between the first time you access $_SESSION and the second time. You are accidentally setting it somewhere (using = instead of == is an easy way), or you have code with side-effects that is changing it behind the scenes.