Hello people, i'm realy confused about many things so i hope that somebody here can spend a bit of his time to can teach me about lil things like tell me how can i do to change the name color if any player get certain pvp amounts, or how can i do to change the enchant system of ma server on a progressive decreasing rate, i means, i've spent around 2 days trying to compile something with the "Eclipse" but it's always getting a da**** error that is making me realy angry

and i don't even know what to do, if you can gimme and answer about it or let here a guide about how to do these things i will be realy grateful, anyway, thanks you.
Here is a picture about this error i've mentioned before...
Thanks again for your time.