CAS Server3.2.1 (web.xml + how to add/update login checking)

[Emi Lu]

> . I installed CAS Server 3.2.1
> . installed CAS client 3.1.3  (an typo in my previous mail, it is 3.1.3 not 2.x)

I'd like to know how to update web.xml and adding CAS server side java 
classes to:
==============================================
[1] Login "kerberos username/pwd" checking

[2] After user passes [1]
    Get CAS SSO ticket

Thanks a lot!