รบกวนทีนะคะ bar chart php ติดต่อกับดาต้าเบส MySQLแล้ว error ค่ะ

$con = mysql_connect("localhost","root","1234");

if (!$con) {
  die('Could not connect: ' . mysql_error());
}

mysql_select_db("demo", $con);

$query = mysql_query("SELECT month, wordpress, codeigniter, highcharts FROM project_requests");

$category = array();
$category['name'] = 'Month';

$series1 = array();
$series1['name'] = 'Wordpress';

$series2 = array();
$series2['name'] = 'CodeIgniter';

$series3 = array();
$series3['name'] = 'Highcharts';


while($r = mysql_fetch_array($query)) {
    $category['data'][] = $r['month'];
    $series1['data'][] = $r['wordpress'];
    $series2['data'][] = $r['codeigniter'];
    $series3['data'][] = $r['highcharts'];   
}

$result = array();
array_push($result,$category);
array_push($result,$series1);
array_push($result,$series2);
array_push($result,$series3);

print json_encode($result, JSON_NUMERIC_CHECK);<<< Line 39

mysql_close($con);

print_r($result);
//print json_encode($result, JSON_NUMERIC_CHECK);

//print json_encode($result,JSON_NUMERIC_CHECK); //(ของเดิม)
ลองแก้แบบนี้ดูครับ
print json_encode($result,128);//ของใหม่