Q:

Magento Add translation file to custom theme

i've added a custom translation to my Magento theme like below :
i've add translation.csv in :
app/design/frontend/themename/default/local/ar_SA
and in 
app/design/frontend/themename/default/local/ar_US
the format of translation.csv like below:
"Add To Cart","Buy"
"Add To Compare","Compare"

And from the admin i've choose the local Options for specific language from :
System->Configuration->General->Local Options

But the translation doesn't working !! any suggetions about that ?

A:

Your foldername is 
app/design/frontend/themename/default/locale/ar_SA

Note local > locale

