EntityTakeDamage problem cant track the attacker ?

[kem008]

function hl2c_EntDmg( victim, dmg )
	if victim:IsNPC() and victim:IsValid() and dmg:GetAttacker():IsPlayer() then
		print("Victim: "..victim:GetClass().." took dmg: "..dmg:GetDamage().." attacker: "..dmg:GetAttacker().."")
	end
end
hook.Add("EntityTakeDamage", "hl2c_EntityTakeDamage", hl2c_EntDmg)

I am trying to get the attacker like shooting npc_alyx with crossbow, rpg, combineballs and grenades.
It always give me an error message I though the ulib does it but it is coming from the original lua modules.

[ERROR] gamemodes/half-life-2-campaign/gamemode/init.lua:678: attempt to concatenate a userdata value
  1. v - gamemodes/half-life-2-campaign/gamemode/init.lua:678
    2. unknown - lua/includes/modules/hook.lua:84

Please someone help me. I am trying to block damage by players.

[Gedo789]

You're trying to concat a entity value in a string value.

.." attacker: "..dmg:GetAttacker().."")

Replace this with:

.." attacker: "..dmg:GetAttacker():GetName())

[kem008]

[QUOTE=Gedo789;49893821]You're trying to concat a entity value in a string value.

.." attacker: "..dmg:GetAttacker().."")

Replace this with:

.." attacker: "..dmg:GetAttacker():GetName())

[/QUOTE]

Ye I know I found the solution in a couple of minutes but thanks for the answer :D :D