cancellare automaticamente file vecchi

[myweb77myweb77]

ciao a tutti, utilizzo questo codice per cancellare i file più vecchi di un tot di giorni con php, non so perchè ma mi da pagina bianca. ovviamente il percorso è corretto (../../backup/) e ha i permessi 777

<?
// Define the folder to clean
// (keep trailing slashes)
$captchaFolder  = '../../backup/';
 
// Filetypes to check (you can also use *.*)
$fileTypes      = '*.*';
 
// Here you can define after how many
// minutes the files should get deleted
$day = 6;
$expire_time    = $day * 1440; 
 
// Find all files of the given file type
foreach (glob($captchaFolder . $fileTypes) as $Filename) {
 
    // Read file creation time
    $FileCreationTime = filectime($Filename);
 
    // Calculate file age in seconds
    $FileAge = time() - $FileCreationTime; 
 
    // Is the file older than the given time span?
    if ($FileAge > ($expire_time * 60)){
 
        // Now do something with the olders files...
 
        print "The file $Filename is older than $expire_time minutes\n";
 
        // For example deleting files:
        unlink($Filename);
    }
 
}
?>