need preg_replace help in php
<p>now i want make this
by the <strong>preg_replace</strong></p>

<pre><code>$web = 'site.com';
</code></pre>

<p>i want the preg_replace make it <code>http://www.site.com</code>
and if it
<code>http://site.com</code> no prblem
it whould add http:// in it found in the url
thanks</p>

<p><strong>please i want do that is http:// not exsist</strong></p>
