Web servers can restrict access to certain pages and require users to enter a login name and password. This is referred to as "HTTP Basic Authentication." Web Crossing can use a web server's HTTP authentication system instead of its default authentication system. If you password-protect the directory where the Web Crossing script is, the server will ask the browser for the user's identity when the request is made for a page in that directory. This approach is useful only in an environment when Web Crossing runs as a CGI, and you don't plan to allow guest access.
To turn on browser authentication, go to the Control Panel > User Management > Registered Users and find the section on HTTP Basic Authorization. Check "Support HTTP Basic Authentication".
Note: Guest access is not possible under HTTP Basic Authorization, and users will not be able to register themselves for Web Crossing without any action on your part: you will have to set up and maintain the server-based authorization system.