I want to make a link to another page based on the value inside database column. 
table member
user_id     name    point
--------------------------
 1          sid     90
 2          mike    100 
 3          john    110 
for example, if we click this link <a href="chkpoint.php?user_id=<?php echo $row['user_id']; ?>" >Buy</a> it will check value in point column, if the value  are below or equal than 100 it will go to page buy1.php else it will go to topup.php. so base on table above, for sid click Buy link, he will go to topup.php and for mike and john click Buy link they will go to buy1.php. so how can i create chkpoint.php? so far this is my code for chkpoint.php
<?php
$conn = new PDO('mysql:host=xxx; dbname=xxx', 'xxx', '') or die(mysql_error());
if (isset($_GET['user_id']) && !empty($_GET['user_id'])) {
    $user_id = $_GET['user_id'];
    $stmt = $conn->prepare('SELECT * FROM member WHERE user_id =:user_id');
    $stmt->execute(array(':user_id'=>$user_id));
    $row = $stmt->fetch(PDO::FETCH_ASSOC);
    extract($row);
} else {
    header("Location: memrec.php");
}
if (isset($_GET['point']) <= "100") {
    header("Location: topup.php");
} else {
    header("Location: buy1.php");
}
?>
but that code above doesn't working.
 
     
    