random foto senza il tasto F5

[LedGiallo]

Salve, come faccio ad fare il refresh della pagina dove ho un blocco e ci stanno le foto in random :
ecco il codice in php:

<?php 
$ok = false;
$stmt = $db->prepare("SELECT photo_categories.title as _title,  photo_categories.id as _id,  photo_categories.dir as _dir , photo.*, DATE_FORMAT(photo.data_reg,'%d/%M/%Y ore %H:%i') as 'data_it' FROM photo
           INNER JOIN photo_categories ON photo_categories.id = photo.id_categories WHERE  photo.active=1 ORDER BY RAND() LIMIT 1"); 
$stmt->execute(); 
?>
<div class="menu">
<ul>
<?php
while(($row = $stmt->fetch()) !== false) {
  $ok = true;
?>
<li><a href="photo_view.php?id=<?php echo "".$row["id"].""; ?>"><img src="<?php echo $dir_photo; ?><?php echo $row["_dir"];?>/thumb/<?php echo $row["url"]; ?>"></a></a></li>
<?php
}             
?>
</ul>
<?php   
if (!$ok) {
echo '404';
}
?>
</div>

avete idea come fare? io di javascript ne so poco.

grazie mille.