(the former programmer went away due to a quarel so i can't ask him how he did it)
Well then why not have the new programmer review the code or create something new? I would think a good programmer could whip something up within say a month.
Better would be to integrate some other current authentication system. Not sure of your infrastructure but if Windows and AD then maybe something along these lines
http://www.windowsnetworking.com/articles_tutorials/Authenticating-Linux-Active-Directory.html
