Oh, that is VERY good. Gives me chills. I think I will use that some time in the future. That is similar to a protection scheme that I heard sometime ago, probably on the list.. Hide a special key sequence in your menu system. If the competitor steals your code, then you can call in your trump card right there in front of the jury. > A slave will only accept commands after it has received a message "COPYRIGHT > XXXX" where XXX is the company name and copyright date.