Just paste this code in a header file which is included in the site. You can exclude the fields like description while filtering the POST And GET.
foreach ($_GET as $key => $value) { $_GET[$key] = strip_tags($value); } foreach ($_POST as $key => $value) { $_POST[$key] = strip_tags($value); } foreach ($_SERVER as $key => $value) { $_SERVER[$key] = strip_tags($value); }