function deleteMessage($message_key,$bak_fname)
{
$fp=fopen($bak_fname,'a');
if (!$fp)
throw new RuntimeException("Failed opening backup file ".$bak_fname);
$ref=new LPC_I18n_reference($message_key);
fputs($fp,serialize(LPC_Impex::export($ref)));
fclose($fp);
$result=$ref->delete();
return $result;
}
