[NTG-context] Hiding subanswers

[David Arnold]

All,

We are currently using this as one of our environment files:

\definehead[unnumberedsubsection][subsection]
\setuphead[unnumberedsubsection][number=no,incrementnumber=no]
\defineenumeration[questions][location=serried,text=\blank]
\setupenumerations[questions][before={\page[yes]\unnumberedsubsection 
{Exercises}\startcolumns[n=2]},after=\stopcolumns,number=no]

\defineenumeration[answers][location=serried,text=\blank]
\setupenumerations[answers][before={\unnumberedsubsection{Answers} 
\startcolumns[n=2]},after=\stopcolumns,number=no]

\def\placeanswers{\startanswers\doifmodeelse{short}{\selectblocks 
[shortanswer][criterium=section]}{\selectblocks[longanswer] 
[criterium=section]}\stopanswers}

\defineenumeration[question][location=inleft,text={\color[heavygreen] 
\bgroup}]
\setupenumerations
[question]
[location=inleft,
   text={\color[heavygreen]\bgroup},
   stopper={.\egroup},
   way=bysection,
   sectionnumber=no]

\defineenumeration[subquestion][location=hanging,text={\color 
[heavygreen]\bgroup},conversion=characters]
\setupenumerations[subquestion][stopper={.\egroup}]

\defineenumeration[answer][location=inleft,text={\color[heavygreen] 
\bgroup}]
\setupenumerations
   [answer]
   [location=inleft,
    text={\color[heavygreen]\bgroup},
    stopper={.\egroup},
    way=bysection,
    sectionnumber=no]

\defineenumeration[subanswer][location=hanging,text={\color 
[heavygreen]\bgroup},conversion=characters]
\setupenumerations[subanswer][stopper={.\egroup}]

\defineblock[question,shortanswer,longanswer]
\hideblocks[shortanswer,longanswer]


Then we do something like:

\beginquestion
\starquestion
Yada, yada, yada.

\startsubquestion
one part
\stopsubquestion

\startsubquestion
part a
\stopsubquestion

\startsubquestion
part b
\stopsubquestion

\stopquestion
\endquestion


Then we have some answers.

\beginlonganswer
\startanswer

\startsubanswer
part a
\stopsubanswer

\startsubanswer
part b
\stopsubanswer

\stopanswer
\endlonganswer

I'd like to set it up so we could "hide" some subanswers. Any  
suggestions?