Prompt member to sign in

Many of my pages have content that is viewable only to certain membership levels. How do I prompt a member who has access to that level - but who may not be signed in - to sign in?

And...after sign in how do I make sure they are taken back to the page they were on, rather than their user profile?

You can see what i mean here...

http://virtualarts.tv/wiredartsfest/all-festival-pass/

thanks!!!

Kathryn