problem to hook a module

[ps2k11]

Using Prestashop 1.4.4.0

 

duplicated a block advertising module, followed this blog

 

http://alvinjiang.blogspot.ca/2011/01/prestashop-tips-how-to-duplicate.html

 

Trying to display the ad on top of page instead of the right or left side

 

I changed blockads.php

 

if (!$this->registerHook('header') AND !$this->registerHook('top'))

 

shows up in header of pages but ad shows nowhere

 

not sure I'm doing this right