[NTG-context] How should I config the ConTeXt in order to use utf-8 encoding chinese characters?

Dear all Now I can use the GBK encoding chinese characters in my ConTeXt, but if I want to use the utf-8 encoding chinese characters in my tex files, this is, I want the tex source file encoded by UTF-8, how should I config the ConTeXt. BYW, all the chinese fonts needed have been installed correctly by me, including the TTFs and the corresponding Type1 fonts. Thanks --- Hongyi Zhao (赵弘毅) GnuPG DSA: 0xD108493B 老子道德经：第十七章 太上，不知有之；其次，亲而誉之； 其次，畏之；其次，侮之。 信不足焉，有不信焉。悠兮，其贵言。 功成事遂，百姓皆谓：“我自然”。