Q:

How can I get a div content in php

I have a div in php(string) and I want to get the content.
for example:
<div id="product_list" style="width:100%; float:none;">
      <div>
       bla bla bla
      </div>
      bla bla          
</div>

and I want 
<div>
     bla bla bla
</div>
     bla bla

The style is changing, I know only the div id. 
UPDATED
this is my code, same as turbod source and the results are the same too.
so this is the original html
$doc = new DOMDocument();
$doc->loadHTML($buffer);
$id = $doc->getElementById('product_list')

And after this code I get the following: link

A:

Use the php DomDocument class. http://www.php.net/manual/en/class.domdocument.php
$dom = new DOMDocument();

$dom->loadHTML($html);

$xpath = new DOMXPath($dom);
$divContent = $xpath->query('//div[id="product_list"]');

