Erreur code php !

Bonjour,

G cette erreur :

Warning: Invalid argument supplied for foreach() dans le fichier ....\view-competences.php
en cette ligne :

foreach ($res_notselect_competences as $notselected) {
$result .= "<option value='ns-".$notselected['id_competence']."' >".$notselected['nom_competence']."</option>\n";
}
$result .= "</select>";
//$result .= $form->creer_bouton($param["action"]["view"],'bt_view','button');

$result .= "<div id='bodycontent'></div>";


$result .= $form->creer_bouton($param["action"]["update"],'','submit','button');

$result .= $form->form_end();

echo $result;



..... et j'avais deja ça :

$req_notselect_competences = "SELECT ".$param["table"]["competence"];
$req_notselect_competences .= ".id_competence,nom_competence FROM ";
$req_notselect_competences .= $param["table"]["competence"]." ";
$req_notselect_competences .= "WHERE ".$param["table"]["competence"].".id_competence ";
$req_notselect_competences .= "NOT IN (".str_replace(",nom_competence", "", $req_select_competences).")";



SVP aidez moi ..