How to forbid users to change their first, last and screen names?

I'm using Wordpress 3.1. I need to forbid users to change the开发者_Go百科ir first, last and screen names in their profile, but admin must still have this possibility. How can I do that?

This is only an ideea ... : you can use validate_username filter, then check if the current logged in user is admin, if not then return false if a user is logged in . Same would apply for the user last and screen names .