nokia mobile series identification by user_agent in http header

[kushks]

hi all,
how to identify mobile series ( specially nokia ) by using user agent string in http header....

i'm trying to get nokia mobile series number by using the user_agent sent by http header, if series is 60 then it is ok i got in users_agent but in case of others i could not identify it.

if someone has idea please help me in this matter.

thanks

kush