please, give me a hand on this one; i'm trying to use autocomplete so user can enter tags by comma separated, example: 'autocomplete, jquery , next , last'

ok, i had the autocomplete working by sending him an $array with all the tags of my website with the previous format aswell,

this is my code:

<?
$a = new etiqueta(0, '');
$b = $a->autocomplete_etiquetas();
mostrar_notificacion('autocomplete_etiquetas_cargado?');
?>
<script type="text/javascript">
    function cargar_autocomplete_etiquetas(){
    $("#tags").autocomplete({
        source: [<? echo $b; ?>]      
    });
}

</script>

All i want it's user to select a tag, apply the ', ' and the autocomplete to be ready for next tag

i'm trying with (i know they are diff id's, also diff inputs):

<?
$b = new ingrediente(0, '');
$c = $b->autocomplete_ingredientes();
?>
<script type="text/javascript">
    function cargar_autocomplete_ingredientes(){
    $("#ingredientes").autocomplete({
        source: [<? echo $c; ?>],
        multiple: true,
        multipleSeparator: ", "


    });
}

</script>

But with out success....

10€ via paypal if answered before 23h (its 21:50 now), it's not much, it's an incentive :P