[Asp.net 2.0] [create user wizard problem]

hi friends,
i am using create user wizard for new user register .. i have added first name, lastname also .. i can insert those values to aspnet_profile table in aspnetdb.mdf database .. but the problem is i want to validate the firstname and lastname textbox controls also .. but its not doing .. how to do that .. then i want to get inserted values from aspnet_profiles table .. how to do this .. plz help me .. any body having idea about this create user wizard control ..