[TYPO3-english] how to : use $message->render(); in v4.5.3?

[Calgacus map Brude]

I need to display a flash message but the message gets gobbled up by another extension when I add it to the flashmessagecontainer, so can I do something like this:

in my controller:

$message = t3lib_div::makeInstance('t3lib_FlashMessage', 'Valid.', 'Message Header', t3lib_FlashMessage::OK, FALSE );
$message->render();
echo "<br/>".__FUNCTION__.__LINE__."<br/>";  
$this->redirect('validate_success');

and have the message show up somewhere on my page, but where, what tag? Or should I handle the passing of messages differently altogether?

I use typo3 v 4.5.3 extbase 1.3 

Thanks