By default, domains added to your account have a small "under construction" page, which simply states that the domain is working, but no content has been uploaded to it yet.  This page is index.html, and will need to be either deleted or replaced before your own site will be displayed.

If you have already removed or replaced this file and the "under construction" page is still showing up, try clearing your browser's cache and refreshing the page.  If it still persists, please contact support so that we may check for any problems on the server.