Script problem (action)

[Master Filip]

Hiho. I want to do script, where player must mine item 8635. If he do it excellent he will mine red crystal (9369), elseif he do it wrong - crystal break to 8639. After some time, this crushed crystal may change back to 8635. I want to do it in second function (addEvent), but script can't find itemEx(8639).
This is script:

function onUse(cid, item, fromPosition, itemEx, toPosition)
	if((itemEx.uid <= 65535 or itemEx.actionid > 0) and isInArray({354, 355}, itemEx.itemid)) then
		doTransformItem(itemEx.uid, 392)
		doDecayItem(itemEx.uid)
		doSendMagicEffect(toPosition, CONST_ME_POFF)
		return true
	end

	if(itemEx.itemid == 7200) then
		doTransformItem(itemEx.uid, 7236)
		doSendMagicEffect(toPosition, CONST_ME_BLOCKHIT)
		return true
	end
	lose = "You totally break the crystal."
	win = "You succesfully mined a red crystal. Hurry up and go to Myuki."
if (itemEx.itemid == 8635) and getPlayerStorageValue(cid, 19101) >= 0 then
if math.random(1, 20) > 19 then
doPlayerAddItem(cid, 9369, 1)
setPlayerStorageValue(cid, 19102,1)
doCreatureSay(cid, win, MESSAGE_EVENT_ORANGE,{x = 1899, y = 2028, z = 8}) -- that position don't matter
elseif math.random(1, 20) < 19 then
doCreatureSay(cid, lose, MESSAGE_EVENT_ORANGE,{x = 1899, y = 2028, z = 8}) -- that position don't matter
doTransformItem(itemEx.uid, 8639)
addEvent(back, 500)

end
end
return false
end
function back(itemEx, item)
if getThingPos(itemid.itemEx) then
doTransformItem(itemEx.uid, 8635)
end
return true
end

That is script of normal pick and my addons.

 

[Zyntax]

addEvent(back, 500, itemEx, item)

this should do it, perhaps