The user-new page called a proc in the authentications package which checked
to see if a parameter was set or not. However, in upgraded sites, or if
the user had entered a blank entry for the parameter, the proc would bomb.
I made the proc more robust by using string is false instead of ![parameter...
and also added in a util_user_message to make it more explicit what is happening
if you aren't able to register (the behavior was very confusing).