If you know how to multithread you can easily make a listener in a new class that implements Runnable. You can basically make this new thread constantly watch your inventory slots and check if anything changes, or whatever you are trying to make it do. Just make a new class that implements Runnable, make that class do whatever you want, then in Script thread, Thread thread = new Thread(ClassName) then start the thread. I haven't used that in a while, but its something like that. Just look up the basics of multi threading and you can easily find how to make it. ^_^