praticamente sono riuscito a trovare questo script, però fa solo operazioni tra interi, ma se volessi farlo con i decimali, con la virgola per capirci?
codice:
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
<script src="http://www.pengoworks.com/workshop/jquery/field/jquery.field.js"></script>
<script src="http://www.pengoworks.com/workshop/jquery/calculation/jquery.calculation.js"></script>

<form name="form1" method="post" action="">
<div id="formContent">
<table width="500">
<COL style="width: 50px;">
<COL>
<COL style="width: 60px;">
<COL style="width: 110px;">
<tbody>
<tr>
<th width="179">Qty</th>
<th width="164" align="left">Product</th>
<th width="72">Pri ce</th>
<th width="65">Total</th>
</tr>
<tr>
<td align="center">
<INPUT name="qty_item_1" type="text" class="input" id="qty_item_1" value="1" size="5">
</td>
<td>Table</td>
<td align="center" id="price_item_1">$150</td>
<td align="center" id="total_item_1">$</td>
</tr>
<tr>
<td align="center">
<INPUT name="qty_item_2" type="text" class="input" id="qty_item_2" size="5">
</td>
<td>Pencil</td>
<td align="center" id="price_item_2">$100</td>
<td align="center" id="total_item_2">$</td>
</tr>
<tr>
<td align="center">
<INPUT name="qty_item_3" type="checkbox" id="qty_item_3" value="1,3">

</td>
<td>Toys</td>
<td align="center" id="price_item_3">$25</td>
<td align="center" id="total_item_3">$</td>
</tr>
<tr>
<td align="center">
<select name="qty_item_4" id="qty_item_4">
<option selected="selected">Select an option</option>
<option value="1">Book1</option>
<option value="1">Book2</option>
<option value="1">Book3</option>
</select>
</td>
<td>Books</td>
<td align="center" id="price_item_4">$10</td>
<td align="center" id="total_item_4">$</td>
</tr>
<tr>
<td colspan="3" align="right">Grand Total:</td>
<td align="center" id="grandTotal">$</td>
</tr>
</tbody>
</table>
</div>
</form>
<script>$(document).ready(function() {
$("#idPluginVersion").text($.Calculation.version);
$("[name^=qty_item_]").bind("change keyup", recalc);
recalc();
});

function recalc() {
$("[id^=total_item]").calc(
"qty * price",
{
qty: $("[name^=qty_item_]"),
price: $("[id^=price_item_]")
},
function (s) {
return "$" + s.toFixed(2);
},
function ($this) {
var sum = $this.sum();
$("#grandTotal").text("$" + sum.toFixed(2));
}
);
}</script>
Sapete dirmi per favore come fare?
grazie ancora