Contact Us is Gone after editing

I hope someone can help...
Fortunately I backed up my site before attempting to make changes per Simple CSS/PHP AntiSpam Solution for your contact form instructions. I made the suggested changes and when I checked they did not work.
So I restored from my backup. My Contact Us still does not work. I then restored back to the prior backup and the same thing. I get the same message:
The website cannot display the page
HTTP 500
Most likely causes:
•The website is under maintenance.
•The website has a programming error.

What you can try:
Refresh the page.

 Go back to the previous page. 

 More information 

So I am now wondering how long it has been since Contact Us did work. Any help/suggestions would be appreciated. Instead of trying to prevent any possible spamming, I've managed to stop all Contact Us emails.:oops:

Search the tutorials for 500 server errors

kobra:

Search the tutorials for 500 server errors

Thank you Kobra for the pointer where to start looking. I have filed an incident with GoDaddy just in case they have made some sort of changes that I was not aware of. Plus it seems I cannot access error logs for my account myself so I requested them as well from GoDaddy.

I have filed an incident with GoDaddy
Search this forum for them and all the issues they cause

They are not a sound ecommerce host