[Javascript/PHP] Ed ora come faccio?

[CamilloCorleone]

Salve a tutti!

Questo è il lavoro che ho per le mani:


Ottenuto da questo codice (solo 1 tabella delle tre): [i "value" sono settati in quel modo perché mi servono, vengono mandati via mail per informare il negoziante dell'ordine fatto]

<table>
<tbody>
<tr>
<th colspan="3">ABITI E INDUMENTI VARI</th>
</tr>
<tr>
<td>Camicia LS PI</td>
<td><label id="prezzo">€3,50</label></td>
<td><select name="art1" ><option value="">0</option><option value="1 x Camicia LS PI">1</option><option value="2 x Camicia LS PI">2</option><option value="3 x Camicia LS PI">3</option><option value="4 x Camicia LS PI">4</option><option value="5 x Camicia LS PI">5</option><option value="6 x Camicia LS PI">6</option><option value="7 x Camicia LS PI">7</option><option value="8 x Camicia LS PI">8</option><option value="9 x Camicia LS PI">9</option><option value="10 x Camicia LS PI">10</option></select></td>
</tr>
<tr>
<td>Camicia LS PI</td>
<td><label id="prezzo">€3,50</label></td>
<td><select name="art1" ><option value="">0</option><option value="1 x Camicia LS PI">1</option><option value="2 x Camicia LS PI">2</option><option value="3 x Camicia LS PI">3</option><option value="4 x Camicia LS PI">4</option><option value="5 x Camicia LS PI">5</option><option value="6 x Camicia LS PI">6</option><option value="7 x Camicia LS PI">7</option><option value="8 x Camicia LS PI">8</option><option value="9 x Camicia LS PI">9</option><option value="10 x Camicia LS PI">10</option></select></td>
</tr>
<tr>
<td>Camicia LS PI</td>
<td><label id="prezzo">€3,50</label></td>
<td><select name="art1" ><option value="">0</option><option value="1 x Camicia LS PI">1</option><option value="2 x Camicia LS PI">2</option><option value="3 x Camicia LS PI">3</option><option value="4 x Camicia LS PI">4</option><option value="5 x Camicia LS PI">5</option><option value="6 x Camicia LS PI">6</option><option value="7 x Camicia LS PI">7</option><option value="8 x Camicia LS PI">8</option><option value="9 x Camicia LS PI">9</option><option value="10 x Camicia LS PI">10</option></select></td>
</tr>
<tr>
<td>Camicia LS PI</td>
<td><label id="prezzo">€3,50</label></td>
<td><select name="art1" ><option value="">0</option><option value="1 x Camicia LS PI">1</option><option value="2 x Camicia LS PI">2</option><option value="3 x Camicia LS PI">3</option><option value="4 x Camicia LS PI">4</option><option value="5 x Camicia LS PI">5</option><option value="6 x Camicia LS PI">6</option><option value="7 x Camicia LS PI">7</option><option value="8 x Camicia LS PI">8</option><option value="9 x Camicia LS PI">9</option><option value="10 x Camicia LS PI">10</option></select></td>
</tr>
<tr>
<td>Camicia LS PI</td>
<td><label id="prezzo">€3,50</label></td>
<td><select name="art1" ><option value="">0</option><option value="1 x Camicia LS PI">1</option><option value="2 x Camicia LS PI">2</option><option value="3 x Camicia LS PI">3</option><option value="4 x Camicia LS PI">4</option><option value="5 x Camicia LS PI">5</option><option value="6 x Camicia LS PI">6</option><option value="7 x Camicia LS PI">7</option><option value="8 x Camicia LS PI">8</option><option value="9 x Camicia LS PI">9</option><option value="10 x Camicia LS PI">10</option></select></td>
</tr>
</tbody>
</table>

Come diavolo faccio a tirar fuori un totale della spesa sempre aggiornato (prezzi dei prodotti selezionati moltiplicati per la propria quantità)?

[Tuvok-LuR-]

esempio con jQuery
http://jsfiddle.net/J6GD8/1/

$('select').on('change', function () {
    var tot = 0;
    $('select').each(function () {
        var q = +$(':selected', this).html();
        var p = $(this).parent().prev().find('label').html();
        var i = +p.slice(1).replace(',', '.');
        tot += i * q;
    });
    $('#tot').html(tot);
});

ti consiglio di aggiungere un attributo data-price alla select in modo da rendere la cosa piu semplice e meno dipendente dal markup:
http://jsfiddle.net/J6GD8/3/