SQLSTATE [3D000]: Invalid catalog name: 1046 No database selected

<?PHP

// Keep users, passwords, and hosts secret.Configuring separately.
$db_user="xxxxxxxxxx";
$db_pass="xxxxxxxxxx";
$db_host="xxxxxxxxxx";
$db_name = "phptx";
$db_type="mysql";

$dsn="$db_type:host=$db_host;db_name=$db_name; charset=utf8";

try{
    $pdo = new PDO($dsn, $db_user, $db_pass);
    $pdo->setattribute(pdo::ATTR_ERRMODE,
                pdo::ERRMODE_EXCEPTION);
    $pdo->setattribute(pdo::ATTR_EMULATE_PREPARES, false);
    print "Connected";

} catch(PDOexception$Exception){
    die('Error 1:'.$exception->getMessage());

}

try{
    $pdo->beginTransaction();
    $sql = "insert into member(last_name, first_name, age) values(:last_name,:first_name,:age)";
    $stmh = $pdo->prepare($sql);
    $stmh->bindvalue(':last_name',$_post['last_name'],pdo::param_str);
    $stmh->bindvalue(':first_name',$_post['first_name'],pdo::param_str);
    $stmh->bindvalue(':age', $_post['age'], pdo::param_int);
    $pdo->execute();
    $pdo->commit();
    print "Inserted ".$stmh->rowcount()" data.<br>";
} catch(PDOException$exception){
    $pdo->rollback();
    print "Error 2:".$exception->getMessage();
}

?>

 Connected Error 2: SQLSTATE [3D000]: Invalid catalog name: 1046 No database selected