How to use language select?

[tyt]

Please hepl me!
I installed SMF 1.1 RC3, and install Vietnamese package successful. But on my forum, funtion Language Select don't display! How can i do to fix this problem?
Thanks!

[chipset66]

In Admin>>Configuration>>Features and Options>>Basic Features have checkbox "Enable user-selectable language support". This must checked!
And Admin>>Configuration>>Server Settings>>Core Configuration have "Default Forum Language", there choose your language.