install language pack in magento

In magento to make multilanguage store work properly  we need to add a language pack in magento by default it has only english language for frontend 

to make it work we have to download the language pack and upload it to root directory

we can download the language pack from this url http://www.magentocommerce.com/translations here select your desired language and download it . In which you willl get a app folder , just upload it to root directory or merge into your app folder  and now go to admin -> system-> configuration -> you will see something like this

now click on locale tab under general  you will see something like this 

now in locale select box choose your language for which you have upload the language pack and its done .