Facebook App, required login

I have made a Facebook App - iframe [login to view URL] in the end i want a facebook app where the user can download a PDF before downloading the PDF the user has to be loggedin into facebook and grant access, so the application can grab his email address and save this email address in our database im looking someone who can make me this application and help me installing this - ASP.net in VB.net application (iframe will be installed on [login to view URL]) - application allows to download a PDF, but before downloading a popup will ask for access so we can get the users email address and save it our database SQLserver 2008