store(&VERSION) '10.0'
store(&NAME) 'testvariable'
store(&COPYRIGHT) '©'
store(&KEYBOARDVERSION) '1.0'
store(&TARGETS) 'any'
store(&LAYOUTFILE) 'testvariable.keyman-touch-layout'

store (myVar) "1"
store(&VISUALKEYBOARD) 'testvariable.kvks'

begin Unicode > use(main)

group(main) using keys

+ [K_S] > "(+)" set(myVar="1")    c  S will Set the variable, and output (+)
+ [K_C] > "(-)" set(myVar="0")    c  C will Clear the variable, and output (-)
if (myVar = "1") + [K_R] > "+"    c  R will Reveal the variable's state with + or - 
if (myVar!= "1") + [K_R] > "-"