[HELP] Weed harvesting loop

So Im trying to do a weed harvesting loop by putting something like this but it doesnt work:

Citizen.CreateThread(function()
  while xPlayer.canCarryItem('weed', 420) do
    xPlayer.addInventoryItem('weed', 1)
    Citizen.Wait(1500)
  end

I already have a key when pressed the weed harvest starts.
Im also trying to add this code that stops the harvesting process when pressing certain keys but I dont know how to do it exactly:

if IsControlPressed(0,8) or
   IsControlPressed(0,28) then
break

And finally a message warning the player his inventory limit when carrying weed:

if not xPlayer.canCarryItem('weed', weed.weight) then
	  xPlayer.showNotification(_U('inv_full_weed'))
end

That’s all I need, if anybodie can help me I’ll be gratefull. Thanks! (Sorry for my english btw)

Problem solved changing the extendedmode version.