function calcOrder() {
    var order_total = 0;
	for (var i=0; i < document.order.elements.length; ++i) {
        form_field = document.order.elements[i];
        form_name = form_field.name;
        if (form_name.substring(0,10) == "totalPrice") {
			line_total = parseFloat(form_field.value);
			order_total += line_total;
        }
    }
	totalOrder = document.order.elements["totalOrder"];
    totalOrder.value  =order_total.toFixed(2);
}

function calcTotal(item) {
  price = document.order.elements["price"+item];
  quantity = document.order.elements["quantity"+item];
  totalPrice = document.order.elements["totalPrice"+item];
  totalPrice.value=(price.value*quantity.value).toFixed(2);
  calcOrder();
}