This is my first scraper https://scraperwiki.com/scrapers/my_first_scraper_1/
I managed to scrape google.com but not this page.
http://subeta.net/pet_extra.php?act=read&petid=1014561
any reasons why?
I have followed the documentation from here.
https://scraperwiki.com/docs/php/php_intro_tutorial/
And there is no reason why the code should not work.
It looks like you are specifying to find a specific element. Elements change dependent on the site you are scraping. So if it doesn't find the element you are looking for you get no return. Also I would look into creating your own scraping/spidering tool with curl. Not only will you learn a lot but you will find out a lot about how to scrape sites.
Also a side not you might want to consider abiding by the robots.txt file on the website you are scraping from or ask permission before scraping as it is considered impolite.