Wordpress Site Stopped Working

I have a wordpress site for a client that was working fine until last night. I made some changes to one of the pages (which wasn't part of wordpress) and suddenly today only the homepage works. None of the links for wordpress are working. I've tried putting on backed up copies but can't seem to get it to work. I need someone who is an expert on wordpress to look into this. ## Deliverables * * *This broadcast message was sent to all bidders on Wednesday Aug 25, 2010 1:41:12 PM: The url of the website can be seen here: [login to view URL] This page works fine, but click any link and it doesn't work. It did work 24 hours ago. The only change I made was in [login to view URL] (which isn't part of wordpress - this page currently works fine). Please let me know if you have anymore questions.