OnSpawningEntity

[tonibm19]

I'm trying to make a plugin that makes sure mobs spawn in the right biome.
Here's the code.

Code:

function OnSpawningEntity(World, Entity)
    if (Entity:GetClass() == "wolf" and World:GetBiomeAt(Entity:GetPosX(),Entity:GetPosZ()) ~= 4) then  
        Entity:Destroy()
    end
end

It don't works, wolves spawn everywhere.
I don't get any error in console