Проверка пустого поля input

$("#confirm-button-next").on("click", function() { 
  $("div.error").remove(); 
  if ($("#order_fio").val().length < 1) { 
    $("#order_fio").after('<div class="error">Заполните поле Ф.И.О!</div>'); 
    setTimeout(function(){$("div.error").remove();}, 5000); 
    return false; 
  } 
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 
<div class="field__input-wrapper"><label class="field__label field__label--visible" for="checkout_shipping_address_first_name">Ф.И.О</label> 
  <input name="order_fio" placeholder="Ф.И.О" autocomplete="shipping given-name" data-backup="first_name" class="field__input" size="30" type="text" id="order_fio"> 
</div> 
 
<button style="margin-top:15px;" type="submit" name="submitdata" id="confirm-button-next" name="button" type="submit" class="step__footer__continue-btn btn"> 
  <span class="btn__content">Оформить заказ</span> 
  <i class="btn__spinner icon icon--button-spinner"></i> 
</button>