determining users' access by their membership roles

im currently developing a website, and i want to enforce security by observing membership roles.
i have these roles set in the asp.net website configuration tool,
now here's what i want to do,
i have a login control and i want it to filter users by their roles, to determine the user's access like:

if your role is Staff, you can access the StaffMain.aspx inside the secure_staff folder
and if you are a Customer, you can only access the Customer.aspx inside the secure_customer folder,
and before they go to their respective page, is it possible to add a redirection page like in most forums out there? 
can you teach me how or can asked for codes? only Visual Basic 2005 codes, because its our thesis requirement, thanks

 
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