[NTG-context] tikz

Hello, i try to use tikz: \usemodule[tikz] \usebodyfont [sansserif, 10pt] ... \starttikzpicture[] \draw (0cm, 0cm) -- (5cm, 5cm) node {vous êtes ici}; \stoptikzpicture the text in the figure is not 'sansserif' but cmr-like. How can I get the same 'sansserif' than in the body ? Thanks for your help. -- René Bastian