Проверка группы пользователя в AJAX?

<?php

@error_reporting ( E_ALL ^ E_WARNING ^ E_NOTICE );
@ini_set ( 'display_errors', true );
@ini_set ( 'html_errors', false );
@ini_set ( 'error_reporting', E_ALL ^ E_WARNING ^ E_NOTICE );

define( 'DATALIFEENGINE', true );
define( 'ROOT_DIR', substr( dirname(  __FILE__ ), 0, -12 ) ); // /engine/ajax/
define( 'ENGINE_DIR', ROOT_DIR . '/engine' );

include ENGINE_DIR . '/data/config.php';

if( $config['http_home_url'] == "" ) {
	$config['http_home_url'] = explode( "engine/ajax/allvotes.php", $_SERVER['PHP_SELF'] );
	$config['http_home_url'] = reset( $config['http_home_url'] );
	$config['http_home_url'] = "http://" . $_SERVER['HTTP_HOST'] . $config['http_home_url'];
}

require_once ENGINE_DIR . '/classes/mysql.php';
require_once ENGINE_DIR . '/data/dbconfig.php';
require_once ENGINE_DIR . '/modules/functions.php';

dle_session();

// Определение групп пользователей
$user_group = get_vars("usergroup");

if( !$user_group ) {
	$user_group = array ();

	$db->query( "SELECT * FROM " . USERPREFIX . "_usergroups ORDER BY id ASC" );
	
	while ( $row = $db->get_row() ) {
		$user_group[$row['id']] = array ();
		
		foreach ( $row as $key => $value ) {
			$user_group[$row['id']][$key] = stripslashes($value);
		}
	}
	set_vars("usergroup", $user_group);
	$db->free();
}

$_REQUEST['dle_skin'] = totranslit($_REQUEST['dle_skin'], false, false);

if( $_REQUEST['dle_skin'] ) {
	if( @is_dir( ROOT_DIR . '/templates/' . $_REQUEST['dle_skin'] ) ) {
		$config['skin'] = $_REQUEST['dle_skin'];
	}
}


if( $config["lang_" . $config['skin']] ) {
	if ( file_exists( ROOT_DIR . '/language/' . $config["lang_" . $config['skin']] . '/website.lng' ) ) {	
		include_once ROOT_DIR . '/language/' . $config["lang_" . $config['skin']] . '/website.lng';
	} else die("Language file not found");
} else {
	include_once ROOT_DIR . '/language/' . $config['langs'] . '/website.lng';
}

$config['charset'] = ($lang['charset'] != '') ? $lang['charset'] : $config['charset'];

require_once ENGINE_DIR . '/modules/sitelogin.php';

if( !$is_logged ) $member_id['user_group'] = 5;