Gazelle/sections/reports/ajax_add_notes.php

<?php

if (!check_perms('site_moderate_forums') || empty($_GET['id'])) {
	print
		json_encode(
			array(
				'status' => 'failure'
			)
		);
	die();
}

$ID = (int) $_GET['id'];

$Notes = str_replace("<br />", "\n", $_GET['notes']);
$Notes = db_string($Notes);

$DB->query("UPDATE reports SET Notes = '$Notes' WHERE ID = '$ID'");
print
	json_encode(
		array(
			'status' => 'success'
		)
	);
die();