public function test() { $v = $_POST['val']; $id = $_POST['id']; $category = new Category($id); $old_name = $category->getCategoryName(); $new_name = $v; if (!empty($new_name) && !empty($old_name)) { $category->setCategoryName($new_name); $category->writeData(true); echo $new_name; } else { echo $old_name; } }