getJSON fail on callback

getJSON fail on callback

Hello everybody, i'm really stuck and i think this is the only place to get an answer.

My situation: i use the getJSON request to fill a select (with cities names) after the user have choosen his region.

I paste some code:

  1. <html>
      <head>
    <script type="text/javascript" src="js/jquery.js"></script>

    <script type="text/javascript" charset="utf-8">
    $(function(){
      $("select#reg").change(function(){
        alert ('start');
        alert($(this).val());
        $.getJSON("script/getProvinceRegione",{id: $(this).val(), ajax: 'true'}, function(j){
          alert('callback time!');
          var options = '';
          for (var i = 0; i < j.length; i++) {
            options += '<option value=\"' + j[i].optionValue + '\">' + j[i].optionDisplay + '<\/option>';
          }
          $("select#prov").html(options);
        })
      })
    })
    </script>


      </head>
      <body>

    <form>

    Region: <select id="reg" tal:define="regioni python:context.script.getRegioni()">
    <tal:block repeat="tuplaReg regioni">
    <option tal:attributes="value python: tuplaReg[0]" tal:content="python: tuplaReg[1]"/>
    </tal:block>
    </select>

    City: <select id="prov">
    </select>

    </form>


      </body>
    </html>









































The problem is that callback is never called. I used firebug and i have seen that when i change region the getJSON function is called and my script (python) return this JSON:

[{'optionValue': '03', 'optionDisplay': 'roma'}, {'optionValue': '04', 'optionDisplay': 'milano'}]
 Why my callback is not called? I can't even get the alert ('callback time!'). I thinked that my json could be broken, but firebug net console read and parse it very well, so i think is valid JSON.

I also tried to split up the function declaration from the getJSON request, but it's no use.

Any ideas? In two days I couldn't figure it out!