Do I need a .htaccess redirect?

[Luce]

Hi
I am almost finished the redesign of a site from html using tables and embedded CSS to XHTML strict with external CSS. I have named all of the pages the same as the existing ones but the file extension has changed from .htm to .html.
Does this mean that I will still need to use a redirect to the new url or is there a way around this?
I read something on the W3C site about hiding file extensions but didn't really understand it.
Thanks

[stymiee]

You'll want to use a 301 redirect in .htaccess to make sure users and search engines are taken from the old pages to the new pages. Otherwise they'll get 404 errors if they try to pull up the old pages.

[Luce]

ok thanks