User permissions

[asp30]

I have three user’s lecturers, students and a admin. I want the lecturer to view his three pages the student to view his 4 pages and the admin to view 2 pages as he doesn’t need to view everything.
They shouldn't be able to view each others web pages, can you please tell me how I could do this.
I am using PHP and mysql.

[dagon]

some sort of login system where each has a user level and keep rack of them with sessions, lots of tutorials on this findable via goggle.