Lua My First Script, Could you check it?

[megachock]

Nevermind thanks to all, i have made it work by my own

function onUse(cid, item, fromPosition, itemEx, toPosition)
pos = {x=1656,  y=1135,  z=7}
wall = 1544
level = 50
thing1 = getThingFromPos({pos, stackpos = 1})
          if item.itemid == 1945 and getPlayerLevel(cid) >= level then
                doRemoveItem(getTileItemById(pos,wall).uid)
                doPlayerSendTextMessage(cid,21,"You removed the tile !")
		doTransformItem(item.uid,item.itemid+1)
	elseif item.itemid == 1946 and getPlayerLevel(cid) >= 50 then
		doPlayerSendTextMessage(cid,21,"You have closed the pass!")
		doTransformItem(item.uid,item.itemid-1)
                doCreateItem(wall, 1, pos)
end
return trueÑ
end

With timer:

local pos = {x=1656,  y=1135,  z=7, 1544}
local wall = 1544
local level = 50
local seconds = 3
local event = 0

local function reset(leverPos)
        local lever = getTileItemById(leverPos, 1946).uid
	doTransformItem(lever, 1945)
	doCreateItem(wall, 1, pos)
end

function onUse(cid, item, fromPosition, itemEx, toPosition)


          if item.itemid == 1945 and getPlayerLevel(cid) >= level then
                doRemoveItem(getTileItemById(pos,wall).uid)
                doPlayerSendTextMessage(cid,21,"You removed the tile !")
                event = addEvent(reset, seconds * 1000, getThingPos(item.uid))
		doTransformItem(item.uid,item.itemid+1)
	elseif item.itemid == 1946 and getPlayerLevel(cid) >= 50 then
stopEvent(event)
		doPlayerSendTextMessage(cid,21,"You have closed the pass!")
		doTransformItem(item.uid,item.itemid-1)
                doCreateItem(wall, 1, pos)
end
return true
end

- - - Updated - - -

How i add timer to my script, i mean in 30 seconds the lever will be pulled back and the tile will be created.