site scrape

I've been searching on google this afternoon on how to scrape a website for link tags, but I'm not having much success.

This script,
http://www.merchantos.com/makebeta/php/scraping-links-with-php/

Errors on this line,
// parse the html into a DOMDocument
$dom = new DOMDocument();

I get this error on my page...
Warning: domdocument() expects at least 1 parameter, 0 given in /home/site/www/hello4.php on line 28

I've ventured into an area I'm not to good with, can anyone help?


Thanks...