[NTG-context] times bolditalic in chapter

Hi, probably very basic question. I need the chapter set in bold (and if necessary - see below - in bolditalic). How can this be done when using Times via \usetypescript[postscript] [\defaultencoding] ? \starttext \usetypescript[postscript][\defaultencoding] \setupbodyfont[postscript,10pt] \def\Textit{\groupedcommand\it\/} \def\ChapterStyle{% \switchtobodyfont[rm,20pt] \setupinterlinespace[line=30pt] } \setuphead[chapter] [alternative=paragraph,style=\ChapterStyle] text \chapter{bold heading \Textit{bold italic} bold heading} text \stoptext