<?php
session_start();

include("core/main.php");
	if($_GET['checkNum']){ // if your load with ?checkNum=1 you just want to check if there is anything new (this is for optimization)
		$q = $db->query("select count(*) as nb from t_notification where status is null  AND roles = ".$_SESSION['ROLES']);
		$r = $q->fetchAll()[0];
		echo $r['nb'];
	} else { // otherwhise you want to load the info about the newest notification to display and set the status to 1 so it wont be displayed again
		$q = $db->query("select * from t_notification where status is null AND roles = ".$_SESSION['ROLES']." order by id limit 1");
		$r = $q->fetchAll()[0];
		$db->query("update t_notification set status = 1 WHERE roles = ".$_SESSION['ROLES']."");
		echo $r['info'];
	}
?>