How to make sure the values are increments of 12 in jQuery?

Ok so I have an ajax call that I need to preform if and only if the user has a quantity of 12 because the items are sold as dozens

Here is my html

<input class="items" type="text" name="quantity_26" size="3"></span><br>
<input class="items" type="text" name="quantity_27" size="3"></span><br>
<input class="items" type="text" name="quantity_28" size="3"></span><br>
<input class="items" type="text" name="quantity_29" size="3"></span><br>

here is my jQuery for the ajax call

if(is_mulitple_of_12){
    $.ajax({
        url: 'processing.php',
        type: 'post',
     ...
   ...
}

obviously the is_mulitple_of_12 variable is w开发者_运维百科hat I need a way to find. I was thinking of maybe the Modulus javascript operator but i was wondering if there is a better way

$('input[type=text]').each(function () {

    var total = new Number($(this).val());
    if((total % 12) == 0) {
         /* Is multiple of 12 */
         $.ajax({
              url: 'processing.php',
              type: 'post',
              ...
         });
         ...
    }
    else {
       /* Is not multiple of 12 */
    }
}

where total is the variable that you want to test for multiplicity.

Hope it helps.

EDIT: For your question I understood that you wanted to parse the values from the name attribute and not get the input values, so I fixed this in the code ;)

Test that guess is not 0 and modulo equals zero

var total = 0;
$('.items').each(function() {
    total += parseInt($(this).val() || 0, 10);
});
if (total && total % 12 == 0) {
    // Mulitple of 12
    alert(total);
}

Here's my EDITED example: http://jsfiddle.net/k5cEU/1

1. ) Loop thru each element with class .item
2. ) if the value of that element is null/undefined set it to zero
3. ) parseInt with radix to get the integer representation of the value
4. ) aggregate it to total
5. ) make sure total is not zero & is a multiple of 12

NOTE: (0 % 12 == 0); // true, which you don't want