HTTP 500 error

I recently tried to edit my index template from saying the_content to saying the_excerpt. Unfortunately this made my site crash. Now I get the HTTP 500 message that the site is under maintenance or has a programming error. I was able to undo the coding by pasting the original template in the index template, but I still get the error message. I have no clue how to fix my site.

I checeked the error logs from my host server and this is what it reads: Wed Mar 02 18:16:17 2011] [warn] RewriteCond: NoCase option for non-regex pattern ‘-f’ is not supported and will be ignored.