Best data base design

Hi all,
Can any one of you help me out in giving the ideal database design for the following requirement.
I will be having two heirachy of data. One which can be accesed by the master user and others by clients. There can be n number of clients who can be there. A client can view only his details and the masters.
A master can view data of all the clients and the master. Each clients detail is expected to be kept in a different table.

So in an apllication if the person who logs in is a master user we need to show details of all clients.
If the person logs in as a client A then details of only his table is to be shown.
Can any one get back on this,
Thanking you in advance
VyasFor what its worth ...

I would only use Views to allow them to see the data, and stored procedures to update.

For viewing data, I would create an association table with logins and allowed entities

create table SecurityControl
(
securitycontrol_id int identity not null ,
user varchar(40) not null,
company_no int not null
)


then in the views i would join to it like so:

select
ci.*
from CompanyInfo ci
join SecurityControl si on si.company_no = ci.company_no and suser_name() = si.user


SQL 2000 does have row level security capability but
1. I haven't used it enough to explain it.
2. You didn't specific a version and this solution would be portable to most RDBMS's