#      #### VARS ####

var kb=0
var retflg=0
var value=0

#      #### MAIN ####
label main
print boolean value: 
dumpd value
newline
prline 'n' to change boolean value, or 'q' to quit
keyprompt
set kb

if kb,:q gsub quit
if kb,:Q gsub quit

if kb,:n gsub number
if kb,:N gsub number
goto main

#      #### NUMBER ####
label number
val 0
set retflg
prline press 0 or 1
label number_loop
keyprompt
set kb
if kb,:0 =retflg @1
if kb,:0 =value @0
if kb,:1 =retflg @1
if kb,:1 =value @1
if retflg,@1 return
goto number_loop

#      #### QUIT ####
label quit
stop