User level license scheme for installing app

Hi All,
I developed one business application for which I'm thinking to use user level license scheme, i.e Lets say if someone purchase my software as "5 User License" that means the s/w should not get installed on more than 5 machines.

What are the genaral guidelines to build "x user licnse" product?
Does Java got some API for this?

No.

In general you'd have to talk to a central server to monitor installations.

hmm, thats the one idea which comes to my mind first, but the problem might occurred if user has no internet connectivity.

I'm thinking about if its possible with the "installer" script to keep a local file within installer package and just decrease the counter when installation finished.

How would that help if they installed it on another machine?

David Newton wrote:How would that help if they installed it on another machine?

Forget that, its bad idea. :cry: