function Noaccents($mot) {
	$search=array("a","â","à","é","è","ê","ë","î","ï","ô","ù","ü","û","ç");
	$replace=array("a","a","a","e","e","e","e","i","i","o","u","u","u","c");
	$mot=str_replace($search,$replace,$mot); 
	return $mot;
}



echo Noaccents("Téléchargement");  // Donne : Telechargement

echo Noaccents("$tri_menu['menu_rubrique']"); // Donne Téléchargement

$tri_menu étant un mysql_fetch_array...