HTML page elements alignment and style

First topic message reminder :

Hey guys!

Take a look at the screenshot attached.
What is the correct way to arrange these elements?
So far my style sheet looks like a huge mess /
I am a bit lost with the positions. Especially how to position div ABOVE footer -.-

Screenshot:

I tested on my forum and it works as it should. This code should be added as a new js with placement on all pages.