This may sound stupidly simple, but try clearing your browsers cache. That way it will force everything on the page to be loaded from the server (the updated files) and not from your HD (the older versions of files).
Sorry if that sounds simple, but it catches me out sometimes.
Another drastic measure is to delete ANY ONLINE files.
DO NOT DELETE AND LOCAL CONTENT
After all the ONLINE content is deleted, clear you cache (just to make sure) and then go to your website. With any look you should get either a white sceen, a directory listing or a 403 Forbidden Error (depending on how your web-server is configured)
If you get that then it means that all you ONLINE content has been deleted. Now, you just need to upload your web-pages to your webspace, goto your domain...and voila, it should hopefully work.
This method should really only be used as a last option because the potential for you to loose some or all of your work is high(ish).
Hope this at least helps a bit.