Thanks for the answer.
Maybe you can guide me in the right direction with what I want to achieve: When a visitor is reading a question/answers (not the Ask page which I mistakenly wrote), I would like to make a sidebar fly out when the visitor scrolls down the page, encouraging the visitor to register.
I found this script which I beleve I can use:
http://jeffbrutsche.com/2012/sidebox-fly-out/
Is there a Q&A "template" I can use to insert my own html/javascript/css, and then enable the plugin on the question/answer page with the Anywhere Plugin?
Also, how can I check if the visitor is logged in?