[NTG-context] line numbers in header

Hi there, I'm trying to get a header that contains the numbers of first numbered line on each page and the number of the last numbered line on that page. This is especially useful for poetry. Here is a minimal sample of what I'm trying to do: \setupheadertexts[line--numbers] \starttext \startlinenumbering \dorecurse{50}{\input knuth\par} \stoplinenumbering \stoptext What should I add instead of "line--numbers"? I have tried to search in the reference on the reference manual and the wiki, but I didn't find anything that could help. Many thanks for your help, Pablo -- http://www.oudeis.tk