Users Can See And Edit Their Own Data Only

I have two tables users and employees in the database with the following fields.
users
userid type(int) (primary key)

username type(nvarchar)

password type(nvarchar)
Employees
id type(int)(primary key)

name type(varchar)

designation type(varchar)

userid type(int) (Foreign key)
Both tables are linked with relationships. I want to implement the security that Users can see and edit their own data only. I select this option from security, advanced options tabs. When the user enters the records the list shows the records of all users. I am using ASP Runner. I want that each user should show his own records only and can not able to see the other users data.
thanks in advance