[HELP] I need help for a boss lua script

[simoxx]

Hi all ^^ i am new... i try to create a lua script for my boss but it was a FAIL!!! xD
can you do the script??? ty ^^ (sorry for my bad english i am italian xD)
Fight
Phase 1 100-80% health
Empowered Shadow Bolt (casual target)
Tenebro Shadowfury (casual target)
Tenebro Pyroblast (Main Tank)

Phase 2 80-50% health
Empowered Shadow Bolt (casual target)
Tenebro Pyroblast (Main Tank)
Flash Heal (on boss xD)
Tenebro Shadowfury (casual target)

Phase 3 50-30% health
Change Model (model id : 27082)
Tenebro Lava Burst (Main Tank)
Empowered Shadow Bolt (Casual Target)
Shadowfury (Casual Target)
Fear(Casual Target)

Spell id:
Empowered Shadow Bolt 70281
Pyroblast : 64698
Fear : 5782
Shadow Fury : 45270
Flash Heal :68024

TY for help!!!!! +rep bye!!!

[Deadendz]

Sorry this took a while, I had problems with my server.
But anyways, here it is:

-- Replace inside quotes to make the boss say something when entering combat, killing a target, etc...
-- Leave as "" to say nothing
local Combat_Enter = "I entered combat"
local Combat_Kill = "I killed a target"
local Combat_Dead = "I died"
local Combat_Wipe = "I left combat"
-- Fill in the time between each cast of the spell, in miliseconds (1000 = 1 second)
local Time_ShadowBolt = 6000
local Time_Pyroblast = 10000
local Time_Fear = 12000
local Time_ShadowFury = 8000
local Time_FlashHeal = 15000
-- the entry id for the boss
local entry = 900000
-- the display id before the dragon
local display = 24706

-- Dont change anything after this
kBossk = {}
local Times = {Time_ShadowBolt,Time_Pyroblast,Time_Fear,Time_ShadowFury,Time_FlashHeal}
local Messages = {Combat_Enter, Combat_Kill, Combat_Dead, Combat_Wipe}
local Spells = {70281, 64698, 5782, 45270, 68024}

function kBossk.OnCombat(pUnit, event, pAttacker)
	local sUnit = tostring(pUnit)
	kBossk[sUnit] = {}
	kBossk[sUnit].phase = 1
	pUnit:RegisterEvent(kBossk.Phases, 2000, 0)
	pUnit:RegisterEvent(kBossk.Spells, 2000, 1)
	if(Messages[1] ~= "") then
		pUnit:SendChatMessage(12, 0, Messages[1])
	end
end

function kBossk.OnLeaveCombat(pUnit, event, pLastTarget)
	local sUnit = tostring(pUnit)
	if(Messages[4] ~= "") then
		pUnit:SendChatMessage(12, 0, Messages[4])
	end
	pUnit:RemoveEvents()
	kBossk[sUnit] = {}
	pUnit:Despawn(1000, 20000)
end

function kBossk.OnKilledTarget(pUnit, event, pDied)
	if(Messages[2] ~= "") then
		pUnit:SendChatMessage(12, 0, Messages[2])
	end
end

function kBossk.OnDied(pUnit, event, pLastTarget)
	local sUnit = tostring(pUnit)
	pUnit:RemoveEvents()
	kBossk[sUnit] = {}
	if(Messages[3] ~= "") then
		pUnit:SendChatMessage(12, 0, Messages[3])
	end
end

function kBossk.OnSpawn(pUnit, event)
	pUnit:SetModel(display)
end

function kBossk.Phases(pUnit, event)
	local sUnit = tostring(pUnit)
	if(pUnit:GetHealthPct() <= 80 and kBossk[sUnit].phase < 2) then
		kBossk[sUnit].phase = 2
		pUnit:RemoveEvents()
		pUnit:RegisterEvent(kBossk.Phases, 1000, 0)
		pUnit:RegisterEvent(kBossk.Spells, 100, 1)
	elseif(pUnit:GetHealthPct() <= 50 and kBossk[sUnit].phase < 3) then
		kBossk[sUnit].phase = 3
		pUnit:RemoveEvents()
		pUnit:SetModel(27082)
		pUnit:RegisterEvent(kBossk.Phases, 1000, 0)
		pUnit:RegisterEvent(kBossk.Spells, 100, 1)
	end
end

function kBossk.Spells(pUnit, event)
	local sUnit = tostring(pUnit)
	if(kBossk[sUnit].phase == 1) then
		pUnit:RegisterEvent(function() kBossk.CastSpell(pUnit, 1); end,Times[1], 0)
		pUnit:RegisterEvent(function() kBossk.CastSpell(pUnit, 4); end,Times[4], 0)
		pUnit:RegisterEvent(function() kBossk.CastSpell(pUnit, 2); end,Times[2], 0)
	elseif(kBossk[sUnit].phase == 2) then
		pUnit:RegisterEvent(function() kBossk.CastSpell(pUnit, 1); end,Times[1], 0)
		pUnit:RegisterEvent(function() kBossk.CastSpell(pUnit, 2); end,Times[2], 0)
		pUnit:RegisterEvent(function() kBossk.CastSpell(pUnit, 5); end,Times[5], 0)
		pUnit:RegisterEvent(function() kBossk.CastSpell(pUnit, 4); end,Times[4], 0)
	else
		pUnit:RegisterEvent(function() kBossk.CastSpell(pUnit, 1); end,Times[1], 0)
		pUnit:RegisterEvent(function() kBossk.CastSpell(pUnit, 4); end,Times[4], 0)
		pUnit:RegisterEvent(function() kBossk.CastSpell(pUnit, 3); end,Times[3], 0)
	end
end

function kBossk.CastSpell(pUnit, pSpell)
	if(pSpell == 1) then
		pUnit:CastSpellOnTarget(Spells[1], pUnit:GetRandomPlayer(0))
	elseif(pSpell == 2) then
		pUnit:CastSpellOnTarget(Spells[2], pUnit:GetMainTank())
	elseif(pSpell == 3) then
		pUnit:CastSpellOnTarget(Spells[3], pUnit:GetRandomPlayer(0))
	elseif(pSpell == 4) then
		pUnit:CastSpellOnTarget(Spells[4], pUnit:GetRandomPlayer(0))
	else
		pUnit:CastSpellOnTarget(Spells[5], pUnit)
	end
end

RegisterUnitEvent(entry, 1, kBossk.OnCombat)
RegisterUnitEvent(entry, 2, kBossk.OnLeaveCombat)
RegisterUnitEvent(entry, 3, kBossk.OnKilledTarget)
RegisterUnitEvent(entry, 4, kBossk.OnDied)
RegisterUnitEvent(entry, 18, kBossk.OnSpawn)

Replace the stuff in red with what you want and add to your server.