[NTG-context] No header and no page-number on empty pages

Hi there, there are some possibilities for getting empty pages in a book, f.e. if a new chapter begins (and by settings it may only begin on pages with odd pagenumber). In these cases I want the page-number and the headers to disappear on the empty page, it should be totally empty, if no text is in it. How to achieve that? Thanks Huseyin