The only way to get around the 50 users limit is to authenticate customers against a database rather than rely on NT authentication. This way you may create an unlimited number of users and make the login prompt look the way you want.

Here is an outline of what has to be done:

  1. In the session_onstart procedure in the global.asp redirect to a login script (say, login.asp).
  2. Login.asp would prompt for a password and compare form data to user database and if it matches, it would initialize two session variables - session("user") and session("password").
  3. Every ASP script should be modified to check if the username is valid (alternatively you may simply initialize one session variable, say session("authenticates")=true and save on roundtrips to the user database in all your scripts.) If the check fails, redirect to login.asp.

The technique and is used on many commercial websites and s bulletproof if implemented properly.