When you click lever item on another position disappears

[rsdsebek]

Hi
I tried to make script like in the title, but I couldn't manage to do that. Here is what i wrote:

function onUse(cid, item, frompos, item2, topos) 
    if item.uniqueid == 5876 then 
        local barPos = {x = 161, y = 156, z = 5}
        local bar = getTileItemById(barPos, 1547).uid
        doTransformItem(bar, 0)
        return TRUE
    end 
    return FALSE
end

Unfortunately I keep getting no errors in console, so I don't know what's going on. Second case is changing tile. I want to change floor item (for example grass to dirt) when I click lever on another position. Can anyone help me with that?

Best
Sebastian