hvad er min fejl

Jeg sætter 4 stjerner ud for den linie der er fejl i.

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in

<?php

mysql_connect("xxx","xxx","xxx");
mysql_select_db("xxx");

$hent =mysql_query("SELECT * from besked ORDER BY id");
**** while($row =mysql_fetch_array($hent)) {

echo '<table border="0" cellpadding="0" cellspacing="0" width="350">';
echo '<tr><td>datoer</td><td>Afsendere</td><td>Beskeder</td></tr>';
echo '<tr><td>'. $row['dato'] .'</td><td>'. $row['navn'] .'</td><td>'. $row['besked'] .'</td></tr>';
echo '</table>';
}
?>