2 Autocomplete problems

2 Autocomplete problems

I have 2 problems getting an Autocomplete to work. First, the term is not passing to the php script to modify the query as the user types.  Second, the ajax success response is not properly created so no dropdown appears for selection. I have modeled the ajax success on the JSONP example in the Autocomplete documentation section, but it doesn't work for me.  According to Firebug, the php does execute a query (but not using 'term') and create JSON. Here's the code. Any help would be appreciated.

jQuery:

        $("#stateProvince").autocomplete
        ({
            source: function( request, response )
            {            
                //build an object identifying the selected country
                //Pass the selected country to query manager to limit selection to that country                             
                var countryFilter=$.post("getStateProvince.php", { "countryAbbrev": $('input[name=country]:checked').val() } );   //the filter works and modifies the query
                alert('|' + countryFilter + '|2nd');               
                $.ajax(
                {
                    url: "getStateProvince.php",
                    data: countryFilter,                   
                    type: "POST",  // a jQuery ajax POST transmits in querystring format in utf-8
                    dataType: "json",   //return data in json format                                                                               
                    error: function(x,y,z) {
                           alert(x+'\n'+y+'\n'+z);
                           },                                                                       
                    success: function( return_arr )
                    {
                        console.log(return_arr);
                        response( $.map( return_arr.getStateProvince, function( item )
                        {
                            return{
                                    value: item.value,
                                    abbrev: item.abbrev
                                   }
                        }));
                    }
                });               
            },
            minLength: 2
        });

selected php statements:
/* checking on term  */
$term=$_GET['term'];
var_dump($_GET['term']);  /* Firebug shows this NULL */

/* build and send response array formated JSON  */
        while ($row = mysql_fetch_array($fetch, MYSQL_ASSOC))
        {
    /* In each row, pull stateProvinceNameInEnglish and stateProvinceAbbreviation. */
            $row_array['value'] = $row['stateProvinceNameInEnglish'];
            $row_array['abbrev'] = $row['stateProvinceAbbreviation'];
           
            array_push($return_arr,$row_array);
        }

  echo json_encode($return_arr);