worldobject:RegisterEvent error on indexing worldobject

When I attempt to use the examples shown on site for making a worldobject registerevent I get an error on the worldobject, implying it is a nil value like so:

lua_scripts/test.lua:5: attempt to index global 'worldobject' (a nil value)

Tried a few different examples with the same outcome, so naturally I expect its probably some oversight on my part.

Tested examples:

local function YourFunction(eventid, delay, repeats, worldobject)
      worldobject:SendUnitSay("My name is " .. worldobject:GetName(), 255)
end
worldobject:RegisterEvent(YourFunction, 10000, 5)

local function Timed(eventid, delay, repeats, worldobject)
    print(worldobject:GetName())
end
worldobject:RegisterEvent(Timed, 1000, 5)

Both return the error stated in the beginning.

You have to specify which worldobject should have the script.

Here is an example for a creature :

local npcID = 100;
local YourNPC = {};

function YourNPC.YourFunction(eventid, delay, repeats, creature)
      creature:SendUnitSay("My name is " .. creature:GetName(), 255)
end

function YourNPC.OnSpawn(event, creature)
    creature:RegisterEvent(YourNPC.YourFunction, 10000, 5)
end

RegisterCreatureEvent(npcID, YourNPC.OnSpawn, 5)

On the creature spawn, the creature will say 5 times "My name is " with 10sec delay. It'll only work for the creature "100" so, don't forget to change the ID.

Official Eluna doc: http://www.elunaengine.com/WorldObject/RegisterEvent.html