[NTG-context] Unicode greek in Context

Hello, I am evaluating context for using it to write long greek documents. So far I have not succeeded in typesetting unicode greek in live-context. I have tried scanning the documentation and mailing list archive with no success. I must admit I am not a very technical user. This is what I have tried so far (unseccessfuly): \enableregime[utf-8] \mainlanguage[gr] \starttext Hello world! Καλημέρα κόσμε! \stoptext Is there something wrong with that? Sorry if I am wasting your time -- if there is a good "RTFM" answer I would not mind. Vassilis