AJAX PHP HTML表单问题[关闭]

I am working on a order form for sandwiches. The four input fields indicate the quantity of the product. (Brown, white bread etc.)

I am looking for suggestions on how to "live" display the products with quantity and price on the bottom of that page.. Also i want to calculate totals. AJAX looks the best way in my opinion; but where do i start?

At this moment the products are static inside html, is it wise to use xml for that? (mysql is not a option at the moment)

I hope this question makes some kind of sense, and will give me some possibilities.

Do you think so you get to have any idea?
A simple example ok? :)
Live: http://jsfiddle.net/WPxgF/

Html:

   <table>
    <tr>
        <td>Product<td>
        <td>Price<td>
        <td>Qtd<td>
    </tr>
    <tr class="item">
        <td>Sandwich<td>
        <td class="price">3.00<td>
        <td class="quant"><input type="text" size="4" value=""/><td>
    </tr>
    <tr class="item">
        <td>Juice<td>
        <td class="price">1.50<td>
        <td class="quant"><input type="text" size="4" value=""/><td>
    </tr>
    <tr>
        <td>Total<td>
        <td><input type="text" size="4" id="amount" value=""/><td>
        <td><input type="text" size="4" id="quant" value=""/><td>
    </tr>
    </table>

Javascript:

  $(document).ready(function(){

        $(".quant input").blur(function(){

            var amount = 0;

            var quant = 0;
            $(".quant input").each(function() {
                var thisQ = this.value;
                quant += Number(thisQ);
                var price = $(this).closest("tr").find(".price").html();
                amount += calcTot(thisQ, price);
            });
            $("#quant").val(quant);
            $("#amount").val(amount);

            $(".price").each(function() {
                price += Number($(this).html());
            });

        });

    });

    function calcTot(quant, price){

        var tot = quant * price;
        return tot;

    }