addEventHandler( "onPlayerSpawn", getRootElement(),
    function (_)
    bindKey(source, "u", "down", "chatbox", "nazwa_funkcji")
    end
) 

function czat(msgtype, msg)
        if (msgtype == 0) then
                cancelEvent()
                local x,y,z = getElementPosition(source)
                for key, gracze in ipairs(getElementsByType("player")) do
                        local x2,y2,z2 = getElementPosition(gracze)
                        if (getDistanceBetweenPoints3D(x,y,z,x2,y2,z2)<17) then
                                local int = getElementInterior(source)
                                local dim = getElementDimension(source)
                                local int2 = getElementInterior(gracze)
                                local dim2 = getElementDimension(gracze)
                                if (int == int2 and dim == dim2) then
                                        outputChatBox("#00CC66".. getPlayerName(source) .." #CC0066krzyczy: #CCFFCC ".. tresc, gracze, 255, 255, 255, true)
                                end
                        end
                end
        end
end
addEventHandler("onPlayerChat", getRootElement(), czat)

addEventHandler("onResourceStart", resourceRoot, function(player)
   bindKey(player,"u", "down", "chatbox", czat)
end)