IP Blacklist Check Script

Listed
'; } } } if (empty($listed)) { echo '"A" record was not found'; } else { echo $listed; } } if (isset($_GET['ip']) && $_GET['ip'] != null) { $ip = $_GET['ip']; if (filter_var($ip, FILTER_VALIDATE_IP)) { echo dnsbllookup($ip); } else { echo "Please enter a valid IP"; } } ?>