function process_categ_index()
 {
     global $dbh;
     $q = "select * from categories ";
     $r = pmb_mysql_query($q, $dbh);
     while ($obj = pmb_mysql_fetch_object($r)) {
         $thes = new categories($obj->num_noeud, $obj->langue);
         $thes->update_index_path_word();
     }
 }