Boss scripting troubles

[CellPunk]

Im attempting to create a boss that slowly because immune to all types of damage except Holy damage, and I was wondering how I would go about this. I have it all compiled, but it decides not to work, or say any sort of errors. I think the first problem would be: How do I cast spells on the boss? So far I have

function Boss_OnCombat(pUnit, event)
pUnit:SendChatMessage(14,0,"You think you can challenge me? The Warrior of Gilneas?!")
pUnit:RegisterEvent("Balth_Phase2",0,0)
pUnit:RegisterEvent("Balth_Phase3",0,0)
pUnit:RegisterEvent("Balth_Phase4",0,0)
pUnit:RegisterEvent("Balth_Phase5",0,0)
pUnit:RegisterEvent("Balth_Phase6",0,0)
end

function Balth_Phase2(pUnit, event)
if pUnit:GetHealthPct() < 84 then
pUnit:RemoveEvents()
pUnit:FullCastSpell(34308)
end
end

function Balth_Phase3(pUnit, event)
if pUnit:GetHealthPct() < 70 then
pUnit:RemoveEvents()
pUnit:FullCastSpell(39804)
end
end

function Balth_Phase4(pUnit, event)
if pUnit:GetHealthPct() < 56 then
pUnit:RemoveEvents()
pUnit:FullCastSpell(34306)
end
end

function Balth_Phase5(pUnit, event)
if pUnit:GetHealthPct() < 32 then
pUnit:RemoveEvents()
pUnit:FullCastSpell(34309)
end
end

function Balth_Phase6(pUnit, event)
if pUnit:GetHealthPct() < 18 then
pUnit:RemoveEvents()
pUnit:FullCastSpell(34311)
end
end

function Balth_OnLeaveCombat (pUnit, Event)
pUnit:SendChatMessage(12,0,"Once again, I have bested you... Inferior beings.")
pUnit:RemoveEvents()
end

function Balth_OnDied (pUnit, Event)
pUnit:SendChatMessage(11,0,"You may have slain me, but I live on.")
pUnit:RemoveEvents()
end 

RegisterUnitEvent(100000, 1, "Balth_OnCombat")
RegisterUnitEvent(100000, 2, "Balth_OnLeaveCombat")
RegisterUnitEvent(100000, 4, "Balth_OnDied")

Meaning, when he hits Less than 56% HP, bump it into Phase4 which will remove that search and cast 34306 (Immune to Frost damage) on himself.

Also, Im getting a server error saying tried to call invalid lua function Balth_OnCombat from ArcEmu (Unit)!, when I have it declared later in the script. Or do I need to declare it first?

[AngelSandy]

First of all, please edit your post and put that script in Code tags.
E.g.

Hey! I am an Example box o.o

Secondly, you are using the wrong function.
You need to do "CastSpell()" not "FullCastSpell()".

Edit that.

Thirdly you wrote "Boss_OnCombat" in your script, but you call "Balth_OnCombat" in your bottom function.

Fix those two issues.

[stoneharry]

It's a good first attempt but you should do what AngelSandy said and read a couple more guides on Lua to check what your doing is correct.
To make mobs imune there are invisible spell auras that you can use, but the easiest and best way is to do it in SQL via going into creature_proto and changing the resistance_1 etc (I cant remember what each one is).

[CellPunk]

It's a good first attempt but you should do what AngelSandy said and read a couple more guides on Lua to check what your doing is correct.
To make mobs imune there are invisible spell auras that you can use, but the easiest and best way is to do it in SQL via going into creature_proto and changing the resistance_1 etc (I cant remember what each one is).

Alright, Ill try Angel's fix. But problem is if I set the Resistances up, he will be immune to all types of damage instantly, instead of slowly becoming immune. My first script used CastSpell() but it didn't work, so then I attempted FullCast, but I totally missed the fact I named my function and register completely different.