Activecodewar was founded by Shahid Mehmood. I am the owner of this blog and working as web developer from last 6 years. I have started to work on magento back in June 2009 and found it very interesting tool to build ecommerce websites. As you will know (if you are magento developer) that it's not easy tool to use, only PHP is not enough to understand it, you need to have full understanding of magento as well.
You can use the following code to get child categories under parent one:
load($parentid);
$childCategories = $parentCat->getChildren(); //Child category IDs separated by commas
?>
