PHP код:
<?php
if(!defined ('FORUMURL'))
{
define('FORUMURL', 'http://www.siliconrp.net63.net');
}
echo "<h1>Hello World!</h1>";
if(defined("FORUMURL")) echo "<li><a href=".FORUMURL.">Forums</a></li>"; else echo "<p> </p>";
?>
You cannot display defines inside quotes.