Изменение кол-ва товаров в корзине при помощи кнопок "+", "-"

<form method="post" class="ms2_form" role="form">
    <input type="hidden" name="key" value="{$product.key}">
    <div class="cartProductCount">
      <div class="cartProductCount__btn cartProductCount__btn--minus">-</div>
      <input type="text" name="count" value="{$product.count}" class="form-control cartProductCount__input">
      <div class="cartProductCount__btn cartProductCount__btn--plus">+</div>
    </div>
    <button type="submit" name="ms2_action" value="cart/change">↻</button>
  </form>

<script>
    (function ($) {
      $(document).ready(function() {
        $('.cartProductCount__btn--minus').click(function () {
          var input = $(this).parent().find('.cartProductCount__input');
          var count = parseInt(input.val()) - 1;
          count = count < 1 ? 1 : count;
          input.val(count);
          input.change();
          return false;
        });
        $('.cartProductCount__btn--plus').click(function () {
          var input = $(this).parent().find('.cartProductCount__input');
          input.val(parseInt(input.val()) + 1);
          input.change();
          return false;
        });
      });
    }(jQuery));
  </script>