function add_review_control() { if (filter_input(INPUT_GET, 'review') && filter_input(INPUT_GET, 'bk') && filter_input(INPUT_GET, 'reviewer')) { $obj = new books(); $review = sanitize_string(filter_input(INPUT_GET, 'review')); $book = sanitize_string(filter_input(INPUT_GET, 'bk')); $reviewer = sanitize_string(filter_input(INPUT_GET, 'reviewer')); if ($obj->add_review($review, $book, $reviewer)) { echo '{"result":1,"message": "review added"}'; } else { echo '{"result":0,"message": "review addition unsuccessful"}'; } } }