UPDATE werkt niet

<?php
include("config.php");

$query = "UPDATE links SET in=in+1 WHERE id = '".$_GET['id']."'";

mysql_query($query) or die (mysql_error());

header("location: index.php");

?>

<?php
include("config.php");
 
$query = "UPDATE links SET in=in+1 WHERE id = '".$_GET['id']."'";
 
mysql_query($query) or die (mysql_error());
 
header("location: index.php");
 
?>