[NTG-context] Fonts switching and styles ..

[Dirar BOUGATEF]

Hi all,

I am working to setup styles in heads with the typeface karat, that i define 
as follows:

\starttypescript [karat]
  \definetypeface [karat] [ss] [sans] [karat] [default] [encoding=texnansi]
\stoptypescript

Here is my head definition:

\setuphead[part]
		  [align=left,
		   page=right,
		   placehead=yes,
		   style=???????,
		   before={\hbox{}\vfill},
		   after={\vfill},
		   command=\MyPart]

Question: what command should i use to define this head to use the karat 
typeface above as its style ?

Thanks for any help.

Dirar.