Putting data from a database into highcharts with $.getJSON

[gabricocchi]

I'm having some problems with $.getJSON, I really need some help because I don't know how to solve the problem and I've been stuck here for days. This is the js file that should generate highcharts when selecting a select option in HTML:

$(document).ready(function() {
$("#paese").change(function(){
    var seriesOptions = [];
        $.getJSON("prova.php", function(data) {
            seriesOptions = data;
        });
var chart1 = new Highcharts.Chart({
    chart: {
        renderTo: 'container',
        type: 'column',
        spacingLeft: 20,
        borderWidth: 1
    },
 ....
 series: [{
        name: 'Italia',
        data: seriesOptions
    }],

Is there anything wrong in the first part? When I select an option, it seems like highcharts don't get the php file, but I'm pretty sure it's correct, here it is(PHP file):

<?PHP 
header("Content-Type: application/json; charset=UTF-8");
$conn = mysql_connect("localhost", "root");
$paese = null;
if(isset($_GET['paese'])) $paese = $_GET['paese'];
$ok = mysql_select_db("liberta", $conn);
$response = array();
$sql="SELECT `valori`.Punteggio FROM `valori` INNER JOIN `nazioni` ON `valori`.Nazione
= `nazioni`.ID WHERE `nazioni`.Nome = '$paese'";
$res=mysql_query($sql);
while($record=mysql_fetch_row($res)){
$response[] = intval("$record[0]");
}
mysql_close($conn);
print(json_encode($response));
?>

I'm trying to get the data from a database I created with PHPmyadmin and put them directly into highcharts, but it doesn't work. I'd be very pleased if you could help me, also because this is is an exam I have to sit. Thank you very much.