As a first step, check the following points:-
Is your domain on the correct name servers? To use our hosting package, your domain name needs to be on our nameservers(ns1.mainnameserver.com & ns2.mainnameserver.com). You can check this on the WHOIS database at http://who.is/. Do note that this may take a little while to update.
If you have purchased hosting, remember that it takes 24 hours for the DNS changes to point your domain at your web space. During this time you can view your site using the temporary URL in your Control Panel.
If your name servers and DNS are correct then check that you have uploaded the files to the public_html folder and make sure the index page has a small [i] in index.html and not Index.html. If your site has a differently named index page (such as index.php or index.cgi), ensure that the default index.html file has been removed.
Also make sure that you have uploaded the files using the right transfer mode: most of the FTP clients check that for you automatically but a few don't. text/script/html files have to be uploaded using text or ASCII Mode. Pictures have to be uploaded using BINARY Mode.
If all of these points have been confirmed, please contact Support who will be happy to assist