blogivan,
<html>
<head>
<script type="text/javascript" src="http://code.jquery.com/jquery-2.1.1.js"></script>
<meta charset="utf-8"/>
<style>
table{
background: #FFF7BF;
border-spacing: 0px;
border: 1px solid #f00;
}
table td{
padding: 10px;
border: 1px solid #f00;
}
</style>
</head>
<body>
<table>
<!--Шапка таблицы************************************ **************************-->
<tr>
<td>Наименование работ</td>
<td>Цена за кг.</td>
<td>Колличество кг.</td>
<td>Сумма</td>
</tr>
<!--Шапка таблицы************************************ **************************-->
<tr>
<td>Картофель</td>
<td class="price_kg">
<span class="value">50</span>
<input name="price" type="hidden" value="50">
</td>
<td>
<input class="input_kg" type="text" name="kg">
</td>
<td>
<span class="dostavka">0</span></td>
</tr><tr>
<td>Картофель</td>
<td class="price_kg">
<span class="value">30</span>
<input name="price" type="hidden" value="30">
</td>
<td>
<input class="input_kg" type="text" name="kg">
</td>
<td>
<span class="dostavka">0</span></td>
</tr><tr>
<td>Картофель</td>
<td class="price_kg">
<span class="value">90</span>
<input name="price" type="hidden" value="90">
</td>
<td>
<input class="input_kg" type="text" name="kg">
</td>
<td>
<span class="dostavka">0</span></td>
</tr><tr>
<td>Картофель</td>
<td class="price_kg">
<span class="value">70</span>
<input name="price" type="hidden" value="70">
</td>
<td>
<input class="input_kg" type="text" name="kg">
</td>
<td>
<span class="dostavka">0</span></td>
</tr>
<!--************************************************** *************************-->
</table>
<div>Общая сумма: <span class="SummAll"></span></div>
<script>
$('.input_kg').on('keyup',function(){
var kg = $(this).val().replace (/\D/gi, '').replace (/^0+/, '');
$(this).val(kg);
var priceKg = $(this).closest("tr").find(".price_kg input[name=price]").val();
var result = Math.round(kg * priceKg);
var priceKg = $(this).closest("tr").find(".dostavka").text(result);
$(".SummAll").html(summAll());
});
function summAll(){
var SummAll = 0;
$(".dostavka").each(function (i) {
var thisSumm = $(this).text();
SummAll = SummAll+(thisSumm*1);
});
return SummAll;
}
$(document).ready(function(){
$("[name=kg]").each(function () {
var kg = $(this).val().replace (/\D/gi, '').replace (/^0+/, '');
$(this).val(kg);
var priceKg = $(this).closest("tr").find(".price_kg input[name=price]").val();
var result = Math.round(kg * priceKg);
var priceKg = $(this).closest("tr").find(".dostavka").text(result);
});
$(".SummAll").html(summAll());
});
</script>
</body>
</html>