[jQuery] form problem

[jQuery] form problem


so the idea is to add a row with an inputfield each time the
inputfield "naam" is filled in.
fore some reason it only adds a new row when i adjust the content of
row 1
any ideas ?
$(function() {
    $(".naam").keyup(function () {
     // json aanroepen
     $.getJSON("producten.js", function(json) {
                var PrijsGezochteNaam = $(".naam").val();
                $.each(json.channel.items,function(i,item) {
                 if (json.channel.items[i].naam == PrijsGezochteNaam) {
                     // index=i; alert(index);
                     PrijsGezochteNaam= json.channel.items[i].prijs;
                            $(".prijs").val(PrijsGezochteNaam);
                            var nieuwerij =
                             $("<tr class='delijn'>"
                                + "<td><input type='text' class='naam' /></td>"
                                + "<td><input type='text' class='aantal' value='1' /></td>"
                                + "<td><input type='text' class='prijs' disabled='true' /></
td>"
                            +"</tr>");
                 $(nieuwerij).appendTo(".prijslijst tbody");
                     }
                    });     // end each json
         });        // end json
});// end keyup
}); // and document.ready
</script>
</head>
<body>
    <form action="" method="" accept-charset="utf-8">
        <table class="prijslijst" border="1">
        <thead>
                <th>Naam</th>
                <th>Aantal</th>
                <th>Eenheidsprijs</th>
                <th>Subtotaal</th>
            </thead>
            <tbody>
            <tr class="delijn">
                <td><input type="text" class="naam" /></td>
                <td><input type="text" class="aantal" value="1"/></td>
                <td><input type="text" class="prijs" disabled="true" /></td>
                <td><input type="text" class="subtotaal" disabled="true" /></
td>
            </tr>
            </tbody>