Code help

I’m creating a little plugin that outputs some html. Here’s what I got so far. Displays the html on all blogs except the main one. What/Where do I need to add code so that it doesn’t display to logged in users.

if ( !defined("ABSPATH") ) {

die("I don't think so, Tim.");

}



global $blog_id;



if ( $blog_id == 1 ) {

return;

}



function test_function () { ?>



<!--HTML CODE HERE -->



<?php }



add_action('wp_footer', test_function');

Thanks