php – jquery附加到输入值

我想要做的是将var大小附加到名为my-item-name的隐藏输入中

我试过添加这个

form.find('[name=my-item-name]').append(size.val());

但它不起作用.

将大小val附加到输入的正确方法是什么？

<form method="post" action="" class="jcart">
    <fieldset>
        <input type="hidden" name="jcartToken" value="13823c48f896c49403465fcce9f135ac" />

        <input type="hidden" name="my-item-id" value="12" />
        <input type="hidden" name="my-item-price" value="15.99" />
        <input type="hidden" name="my-item-url" value="http://yahoo.com" />
        <input type="hidden" name="my-item-name" value="Operation Braveheart hooded sweatshirt" />
        <ul>
            <li>
                <select name="my-select" id="foo12">
                    <option value='Small'>Small</option>
                    <option value='Medium'>Medium</option>
                    <option value='Large'>Large</option>
                    <option value='X-Large'>X-Large</option>
                </select>
            </li>
            <li>Price: $<span id="price12" class="price">15.99</span></li>
            <li>
                <label>Qty: <input type="text" name="my-item-qty" value="1" size="3" /></label>

            </li>
        </ul>

        <input type="submit" name="my-add-button" value="add to cart" class="button" />
    </fieldset>
</form>                
<script type="text/javascript">
    var item_prices_by_size12 = { "Small": { "Price": "15.99","ItemId": "9-1" },"Medium": { "Price": "16.99","ItemId": "9-2" },"Large": { "Price": "17.99","ItemId": "9-3" },"X-Large": { "Price": "18.99","ItemId": "9-4" }};
    $(function() {

        $('#foo12').change(function() {

            var form = $(this).parents('form');

            // Size is whatever the value the user has selected
            var size = $(this).val();

            // Determine the correct price and item ID based on the selected size
            var price12  = item_prices_by_size12[size].Price,itemId = item_prices_by_size12[size].ItemId;

            form.find('#price12').text(price12);

            form.find('[name=my-item-price]').val(price12);

            // Update the item ID
            form.find('[name=my-item-id]').val(itemId);

            form.find('[name=my-item-name]').append(size.val());

        });
    });
</script>