Q&A: What’s the best way to license a web script?

Question by Just P: What’s the best way to license a web script?
I sell a webscript which is written in the php language. What I want to do is create a license for each user and limit the script installation to one domain only.

Also, I want to distribute this same script as a free trial for 15 days. After that the user must upgrade.

What’s the best and “hard to crack” way to distribute license in that way?

Best answer:

Answer by just “JR”
There is no real way, since anyone can edit the script!
However, what you could do is to store the script on YOUR server.
On calling the script, you pass a code (myscript.php?c=xyz)
Your script then first checks xyz against the list of authorised peapole (buyers in a db).
If user is authorized, run the rest of the script.

Know better? Leave your own answer in the comments!