How can I force the choice of the Language?

[Fabiano]

How can I force to all users to choose their native language? Procureu in the AdminCP > Field of User Profiles, however I have not found anything related to the vBET.

I would like this field to be "Required" and was "Required" when he enter in the Forum.

I want all my users to have the full satisfaction in using the vBET.

Thank you!