Facebook Access Via Proxy

Users access Facebook via my proxies (e.g. schoolthrough (.)com ). They log in to facebook as per normal and shown an url of [login to view URL] but nothing of facebook is shown (I dont know why). However if the url is changed to [login to view URL] they have full access. The project is to write a script that where url is [login to view URL] make [login to view URL] and take the user there. If you can suggest some other clever way, by all means suggest.