I'm using the latest version of Zencart (v. 1.3.6)
I created the following overide directories:

includes/languages/english/CUSTOM
includes/templates/CUSTOM/buttons/english/

I coppied the file "button_names.php"

from: includes/languages/english (original dir)

to: includes/languages/english/CUSTOM (my custom dir)

I changed the following parts of the file,
( includes/languages/CUSTOM/buttons/english/button_names.php)

1)The alt tags and
2)I changed some of the link locations directing them to the images i placed inside includes/templates/CUSTOM/buttons/english/

For some reason my images are not showing up on my site rather its using the same original ones from
template_default/buttons/english
also the alt tags did'nt change
any help as to why the overide system isnt working?
Thanx.