accidentally erased .htaccess file in sites/default

Hi everyone,

I had just finished a website, and was trying to move a subdirectory folder to appear as the root folder, per the instructions on http://drupal.org/node/144643.

However, I accidentally erased my .htaccess file in www.example.com/sites/default
When I looked in my backups, I didn't seem to have a copy of the file.
I am now getting Internal Server Errors when trying to access my site.. Is this a critical file?
Does anybody know how to restore this, please? Have I lost everything I've worked on? =/

Thank you very much!