[TigerC10]

Your problem is how you're setting the navbits. $parent isn't defined... You should do this instead...

<?php 

// ####################### SET PHP ENVIRONMENT ########################### 
error_reporting(E_ALL & ~E_NOTICE); 

// #################### DEFINE IMPORTANT CONSTANTS ####################### 
define('NO_REGISTER_GLOBALS', 1); 
define('THIS_SCRIPT', 'Chat'); // change this depending on your filename 

// ################### PRE-CACHE TEMPLATES AND DATA ###################### 
// get special phrase groups 
$phrasegroups = array( 

); 

// get special data templates from the datastore 
$specialtemplates = array( 
     
); 

// pre-cache templates used by all actions 
$globaltemplates = array( 
    'Chat', 
); 

// pre-cache templates used by specific actions 
$actiontemplates = array( 

); 

// ######################### REQUIRE BACK-END ############################

chdir('/path/to/bbs/directory');  
require_once('/path/to/bbs/directory/global.php');

// ####################################################################### 
// ######################## START MAIN SCRIPT ############################ 
// ####################################################################### 

$navbits = array(); 
$navbits["chat.php"] = 'Chat Page'; 

$navbits = construct_navbits($navbits); 
eval('print_output("' . fetch_template('Chat') . '");');

?>

I guess you could also define a $parent variable yourself, if you want - but it's not like you have to.