if (1 > sql_num_rows($resultpersons, $dbi)) {
      echo "Geen items gevonden";
   } else {
      for ($m=0; $m < sql_num_rows($resultpersons, $dbi); $m++) { 
         list($id, $datum, $tijd, $klantid, $description, $addby) = sql_fetch_row($resultpersons, $dbi);
         $resultname = sql_query("SELECT Naam, Voornaam FROM ".$prefix."_probs_klant WHERE id='$klantid'", $dbi);
         list($lastname, $firstname) = sql_fetch_row($resultname, $dbi);
      }
   }