BBS super classic produced by php

BBS super classic produced by PHP (full text here) http://115.com/lb/5lbcqol0flze

$dsn = "mysql:host=localhost;dbname=database name";
$dbh = new PDO($dsn, 'Username', 'Password', array(PDO::ATTR_PERSISTENT => true));
$dbh -> query("SET NAMES 'utf8'; ");

$id=$_POST['id'];
$username = $_SESSION['username']; //Get information about the person who replied
$sql = "select * from user where username= '$username'";
$result = mysql_query($sql);
$row = mysql_fetch_array($result);
$row[ 'score']=$row['score']+2;
mysql_query("update user set score = '".$row['score']."' where username ='".$row['username'] ."'");


$content = $_POST['content'];//Get information about replies
//$email = $row['email'];
$date = date("Y-m-d H :i:s");

$date=date("y-m-d H:i");
date_default_timezone_set("Asia/Shanghai");
$time = date('Y-m-d H:m:s');
$ y=date("Y",strtotime($time));
$m=date("m",strtotime($time));
$d=date("d",strtotime($time));
 $h=date("H",strtotime($time));
$w=date("w",strtotime($time));
//$weekNumber=intval(date('W'));
 //$url = "http://api.map.baidu.com/geocoder?location={$weidu},{$jingdu}&output=json";
//$json = json_decode(file_get_contents($url), TRUE);
//$a=file_get_contents($url);
//$province = $json['result']['addressComponent']['province'];
//$city = $json['result ']['addressComponent']['city'];
$sql=" insert into table name (article ID, content, name, time) values ​​('$id', '$content', '$username', now ())";
//$result=mysql_query($sql);
if ($dbh -> query($sql)) {
 header("Content-Type:Application/json");
 $arr = array('status' => 'ok');
 echo json_encode($arr);
}
?>