Right, heres the rundown.

I have site A, site B and site C. Site A is going to be the main site. This will be the place where people register.

Site B and Site C cannot be accessed without registering at Site A. If someone tries to go to Site B or Site C they get redirected back to Site A.

However, heres another tricky part. Only some members can access site B and only some can access Site C. It all depends on their groups. Site A is open to everyone!

Is this possible?

Reason for doing this?

You can most likley do what you want with one site and use group permissions.

I have a site that allows different ppl to view different areas. Only have one register form and then I place them in the proper group.