dunque, avevo bisogno di fare una semplice select dinamica cosi' googolando ho trovato un esempio semplice che usa javascript. ma nel mio codice c'e' qualche problema che non riesco a scovare.
posto l'originale funzionante ed il mio.
grazie per l'aiuto

codice:
 


<script type="text/javascript">

var shipping = new Object()
shipping["1"] = [{value:"1", text:"Carta di credito"},
                      {value:"2", text:"contrassegno"},
                      {value:"3", text:"Bollettino postale"}];
shipping["2"] = [{value:"1", text:"Carta di credito"},
                      {value:"4", text:"bonifico bancario"}];
shipping["3"] = [{value:"1", text:"Carta di credito"},
                      {value:"4", text:"bonifico bancario"}];

function setCost(chooser) {
    var newElem;
    var where = (navigator.appName == "Microsoft Internet Explorer") ? -1 : null;
    var costChooser = chooser.form.elements["id_pag"];
    while (costChooser.options.length) {
        costChooser.remove(0);
    }
    var choice = chooser.options[chooser.selectedIndex].value;
    var db = shipping[choice];
    newElem = document.createElement("option");
    newElem.text = "tipo di pagamento:";
    newElem.value = "";
    costChooser.add(newElem, where);
    if (choice != "") {
        for (var i = 0; i < db.length; i++) {
            newElem = document.createElement("option");
            newElem.text = db[i].text;
            newElem.value = db[i].value;
            costChooser.add(newElem, where);
        }
    }
}

</script>
<form action="" method="post" name="frmCart" id="frmCart">
<select name="id_area" onchange="setCost(this)">
<option value="" selected="selected">Seleziona un area</option>

<option value="1">Italia</option>
<option value="2">Europa e bacino del Mediterraneo</option>
<option value="3">Paesi extra europei</option>
</select>
</td></tr>
<tr><td colspan="8">
<select name="id_pag" onchange="this.form.submit();">
<option value="" selected="selected">Seleziona il tipo di pagamento</option>
</select>

</form>

codice:
<script type="text/javascript">
var dati = new Objetc() 
dati["2010-06-26"] = [ {value:"0", text:"08:00:00"} ];
dati["2010-06-27"] = [ {value:"1", text:"08:20:00"}, {value:"2", text:"08:00:00"} ];
dati["2010-06-28"] = [ {value:"3", text:"08:20:00"} ];
dati["2010-08-28"] = [ {value:"4", text:"21:20:00"} ];

function setSlot(chooser) {
	var newElem;
	var where = (navigator.appName == "Microsoft Internet Explorer") ? -1 :	null; 
	var slotChooser = chooser.form.elements["slot"];
	while (slotChooser.options.length) {
		slotChooser.remove(0);
	}
	var choice = chooser.options[chooser.selectedIndex].value;
	var db = dati[choice];
	newElem = document.createElement("option");
	newElem.text = "seleziona uno slot:";
	newElem.value = "";
	slotChooser.add(newElem, where);
	if (choice != "") {
		for (var i = 0; i < db.length; i++) {
			newElem = document.createElement("option");
			newElem.text = db[i].text;
			newElem.value = db[i].value;
			slotChooser.add(newElem, where);
		}
	}
}
  

</script>
<table>
 <form action="" method="post" name="frmCart" id="frmCart">
Data:
<select name="data" onchange="setSlot(this)">
<option value="" selected="selected">data</option>
<option value="2010-06-26">2010-06-26</option>
<option value="2010-06-27">2010-06-27</option>
<option value="2010-06-27">2010-06-27</option>
<option value="2010-06-28">2010-06-28</option>

<option value="2010-08-28">2010-08-28</option>

</select>
</td></tr>
<tr><td colspan="8">
Slot:
<select name="slot" onchange="this.form.submit();">
<option value="" selected="selected">Seleziona uno slot</option>
</select>
</form>
</table>