AM: Website? web site? Web-site? website?

["Peter J. Hyszczak" <peterjh@ima-focus.com>]

This may seem like a small thing, but in my recent quest to bring
consistency to a site I am developing I realized that I have seen
Website(?) in every one of the above spellings - often on the same
sites.  I'd apprciate some professional guidance from the group.  What's
the official word for a Web site?