<form  id="form" action="" method="post" class="ajax_form form-feedback ">
<input type="hidden" name="form_name" value="Заказать звонок">
  <div class="contacts__user-name">
    <input id="user_name" type="text" name="name" required>
    <label for="user_name">Имя</label>
  </div>
  <div class="contacts__user-tel">
    <input id="user_phone" type="tel" name="phone" required>
    <label for="user_phone">Телефон</label>
  </div>
  <div class="contacts__user-email">
    <input id="user_email" type="email" name="email">
    <label for="user_email">Email</label>
  </div>
  <div class="contacts__user-comment">
    <textarea id="user_comment" name="message"></textarea>
    <label for="user_comment">Комментарий</label>
  </div>
  <button class="button" type="submit"><span>Отправить</span></button>
</form>