how to add new table to aspnetdb(with membershp tables) database through mvc code first?

Question

Hello,
        I am working with mvc3. I have one database(School) that database has membership tables(Applications,Roles,memberships,Users,UsersinRoles) now i want to add some tables to that School database using mvc code first.and also how to create roles and insert data into users in userin roles.
first i gave connection in web.config like below.
<add name="demodbcontext" Data Source=".; Initial catalog=School;UserId=sa;password=123;MultipleActiveResultSets=true;"ProviderName=
"System.Data.SqlClient"/>

After executing that program it will showing "model compatbility error".

Please send me rpl asap.


thanks in adv
Kiranmai G