Advanced substr method

I am trying to extract a substring from the following text:


<p><a href=“http://www.flickr.com/people/tejana/”>tejana</a> posted a photo:</p>

<p><a href=“http://www.flickr.com/photos/tejana/8034026/” title=“death with dignity”><img src=“http://photos4.flickr.com/8034026_8097013b46_m.jpg” width=“240” height=“180” alt=“death with dignity” style=“border: 1px solid #000000;” /></a></p>

<p>this amazingly deep red is a very rare hollyhock color.</p>


Preferably, I want the substring to be only the path to the photo, specifically: http://photos4.flickr.com/8034026_8097013b46_m.jpg

Does anybody know any thrifty actionscript to extract this substring from the first string?