<p>Moodle requires a PHP version of at least 4.3.0 or 5.1.0 (5.0.x has a number of known problems).</p>
<p>You are currently running version {$a}</p>
<p>You must upgrade PHP or move to a host with a newer version of PHP!<br />
(In case of 5.0.x you could also downgrade to 4.4.x version)</p>