Login form Security

Hello,



I have a login form which works perfectly fine.



Trouble is, i store the login details i.e. username and password in the employees table so technically other users who see this table will be able to login with that users login details..



Is there a way i can tacke this?



Also how do i restrict certain features of my database from users logged in?



The login directs users to the main menu which has buttons directing the user to all features available on the system, But i have dentists for example who should not have access to the registration form which receptionists use..



Another thing is one of the dentists is also the owner who has access to the entire systems features so if there is code involved here please could you bare that in mind:)



Any advice would be appreaciated :)



thank you

Login form Security