[8.4] Npc error function onthink

[T O M E K]

function onThink()
talk = math.random(1,100)
	if talk == 1 then
		selfSay("Only quality steel and wood used for my weapons!")
	end
if talk == 2 then
		selfSay("Give those monsters a good whipping with my weapons!")
	end
if talk == 3 then
		selfSay("Buy your weapons here!")
	end
if talk == 4 then
		selfSay("Selling and buying all sorts of weapons, come and have a look!")
	end
	for i, focus  in pairs(focuses) do
		if(isCreature(focus) == FALSE) then
			removeFocus(focus)
		else
			local distance = getDistanceTo(focus) or -1
			if((distance > 4) or (distance == -1)) then
				selfSay("Um yeah, good day.")
				closeShopWindow(focus)
				removeFocus(focus)
			end
 
		end
 
	end
	lookAtFocus()
end

My error
[c]: in function "pairs"
20 and 6 line