[NTG-context] Why doesn't his URL work?

This code below gets me a working URL, but instead of the word kudos in blue I get the entire URL in my text. Why is that? \setupcolors [state=start] \setupurl [color=blue] \setupinteraction [state=start,color=blue] \useURL[kudos][http://nl.wikipedia.org/wiki/Kudos_(computerterm)][][kudos] \setuppapersize[A4,portrait][A4,portrait] \starttext \url[kudos] \stoptext G