strtolower inside preg_replace - possible?
<p>Is it possible to use <code>strtolower</code> in the substitution part of <code>preg_replace</code>?</p>

<p>This isn’t working:</p>

<pre><code>preg_replace('/(http:\/\/)?(www\.)?([a-zA-Z0-9\-_\.]+\.(com|co\.uk|org|tv|biz)(\/[a-zA-Z0-9\-\._\?&amp;=#\+;]+)*)/i', '&lt;a href="http://www.'.strtolower('$3').'" target="_blank"&gt;'.strtolower('$3').'&lt;/a&gt;', $d);
</code></pre>
