To do it properly is very difficult. It is easy to write some code that
would do it, but that code could be easily cracked. To make it failsafe, you
need to write something in VB, or buy a licensing product, such as
AppSentinel, http://www.thescarms.com/appsentinel/default.asp
--
HTH
Bob Phillips
(replace somewhere in email address with gmail if mailing direct)
