That extra information helps. As I've said, you don't need to worry too much as the (old) homepage link on your default 404 error page does provide -in effect- a redirect to the new domain even if people try to access a page other than the default index, but it could confuse some users. I gather that your new domain is also hosted at Demon? I hadn't realised that when I first replied. From what I remember, their procedures are a bit non-standard. Will your old address there remain active, with ftp access, indefinitely? If that's the case, there are several things you could do to make redirects a little smoother.

Assuming Demon allows it, you could put up a custom 404 page in the (old) root directory with a message to the effect that the whole site has moved, and providing a link to the new domain name index page. Hardly seamless like Redirect 301, but it would be more specific for inexperienced visitors who might not think to try the old homepage link when they get the 'not found' message.

Alternatively, you can put up an .htaccess file that will redirect a request for any page on the old site to its equivalent at the new one. That would be seamless in the way that a request (specific or implied) for the old index page currently is. I've never done one of those myself, but I've done directory redirects between sites and it isn't too complicated if you're careful. The instructions at http://www.gnc-web-creations.com/301-redirect.htm are reasonably easy to understand; see the 'RedirectMatch' section.