in need of code/layout help...

not long ago i was friended by someone who had a super cool feature on their layout: a popup with some disclaimers on it and enter/exit buttons that would appear immediately after their page loads. the popup covered their whole page and there were no glimpses of the profile underneath while loading, the buttons would redirect to the homepage or their profile depending on the response, and the popup would fade out.

unfortunately before i could get the code from them, they disappeared! and now i'm stuck with the desperate desire to add that to my page, and no helpful leads on how.

i've found code for buttons that open a popup on click, but nothing that opens a popup on load with no pre- or post- popup buttons involved. i've had no luck trying to figure it out on my own. anyone know how to help?

open to any advice or leads, i've spent days on this. i have no clue what i'm doing.