[NTG-context] Setupheadertexts with if-condition

Hello mailing list, I want to use an simple if-condition for this code: \setupheadertexts [][][][{\tfx\bf\getmarking[chapternumber] – \getmarking[chapter]}] My problem: In my case the document dont begin with a chapter but with a section. So at the first pages there is not chapter and chapternumber and the "–" is printed alone. So I want something like this: \if\getmarking[chapternumber] {\getmarking[chapternumber] – \getmarking[chapter]} \fi That is of course no valid code. How to implement that if-condition? Thanks! -- Huseyin Özoguz E-Mail: h.oezoguz@mmnetz.de