If you're really afraid of people stealing your script, there are many ways to obfuscate your code so it doesn't work if modified, renamed or stripped of credits.

Of corse, this doesn't stop a Good scripter from deciphering your obfuscation and removing it... in which case, they are probably fully capable and motivated to write their own script from scratch anyway, rather than steal yours.

Well. At least I won lunch.
Good philosophy, see good in bad, I like!