how can I tell if enetity is hidden ?

just give the entity a value of 0 if hidden and 1 if not ie


box = createbox()
boxvisibility = 1

if keyhit(h) and boxvisibility = 1
hideentity box : boxvisibility = 0
endif

if keyhit(j)) and boxvisibility = 0
showentity box : boxvisibility = 1
endif