function.php

I′m currently struggeling. I wanted to create a drop down menu and started messing about with my function.php file, or theme functions, and after updating nothing was working any more. And now I can′t get into my site or anything. I′ve tried to update my server with a fresh function.php right from the wordpress download, but I guess that′s not the way to do it. cause it is still not working.

https://www.equatoraircraft.com

can anyone help me?

Tomas