codice:
$order = "asc"; // Default page 
if (isset($_GET['sort']) && ($_GET['sort']=="asc" || $_GET['sort']=="desc"))  
$order = $_GET['sort'];

if ($order=="asc") {
$orderlink = ("<a href=\"" . $_SERVER["PHP_SELF"] . "?sort=desc\" title=\"Sort the records in descending order\">Sort descending</a>") ;
} else {
$orderlink = ("<a href=\"" . $_SERVER["PHP_SELF"] . "?sort=asc\" title=\"Sort the records in ascending order\">Sort ascending</a>") ;
}
Se scrivi in questo modo non riesco a capire quale sia il problema