php string operation
<p>I have stucked into a typical php string program.
I have a data string like </p>

<pre><code>$str="{heading}
{youtube}4vfOPm6wfyI{/youtube}
{/heading}
&lt;p&gt;Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium&lt;/p&gt;";
</code></pre>

<p>now i want the 4vfOPm6wfyI , the id of the link.
How it will be done?</p>

<p>Thanks </p>
