Updating allowed depending un user.

Hi

I'm using a SQLDataSource and I want to enable or disable update, insert,
select depending on what user that has logged in.

If no user is logged in the data source shouldn't select any data all.

If a viewer las logged (stored as a session cockie) the control should
select data.

If however i with a my username and my password has logged in the datasource
should enalble update, insert, delete and select.

How can I do this. Do I really need to add users with different roles to my
SQL Express database.


Yours
Lars