Display in header only user not logged?

I have a message on the homepage (_header.html) above "__top_menu__" that says "Welcome to the site -- please login or reg!"

Now, after that user logs in, the message should not display. How do I remove the text such that if a user is logged in, the text message don't show up?

A snippet looks like this in _header.html

_banner_top__
<h1 style="color: #459AD3; text-align:center">Welcome to the site! Please login! </h2>
<div class="topMenuWrapper">
__top_menu__
</div>

Anyone?

Provide your injection via key, don`t insert here hardcoded value.

use as example -

__example_message__

key

and process this in design.inc.php file. function PageCode

So you can use PHP code to generate content of this key.