OK, thanks. Now it works, but I've warning: loose indentation.
Before I posted this, I searched about the warning. There were many topics about this, but I still don't understand

In one topic there were something about
if function and the { }, in another topic there were something about free spaces etc.Please, can you explain me about that warning and how can I remove it?
Edit: I tested the plugin. It works, but I don't like that, where is printed the result.
For example:
Mynick <-- this is the result, printed by my plugin
Mynick: /command
Why the result is printed before my nick?