Need help with script!

--can someone DM what I did wrong for this script please?
local Tool = script.Parent;

autolength = 5
enabled = true
enabled2 = true
benabled = true
pgui = nil
mtarg = nil
mousedown = false
target = nil
cart = true
electrictextures = {"http://www.roblox.com/asset/?id=109201383", "http://www.roblox.com/asset/?id=109201366", "http://www.roblox.com/asset/?id=109201474", "http://www.roblox.com/asset/?id=109201980", "http://www.roblox.com/asset/?id=109202011"}

function BarbTouched(hit, barb)
if hit == nil then return end
if hit.Parent == nil then return end
if hit.Parent:findFirstChild("Humanoid") or hit.Parent:findFirstChild("Zombie") ~= nil then
if hit.Parent.Name == game.Players.LocalPlayer.Name then return end
if target ~= nil then return end

if hit.Parent:findFirstChild("OverrideScript") == nil then
	local s = script.Parent.OverrideScript:clone()
	s.Parent = hit.Parent
	target = hit.Parent
s.Disabled = false

if hit.Parent:findFirstChild("Humanoid") ~= nil then
	Tool.LineV.Value = true
	Line = Instance.new("SelectionPartLasso")
print("line")
	Line.Name = "strings"
	Line.Color = BrickColor.new("Black")
	Line.Humanoid = hit.Parent:findFirstChild("Humanoid")
	Line.Part = Tool.Electric
	Line.Parent = target
end
elseif hit.Parent:findFirstChild("Zombie") ~= nil then
	Tool.LineV.Value = true

	Linez = Instance.new("SelectionPartLasso")
	Linez.Name = "strings"
	Linez.Color = BrickColor.new("Black")
	Linez.Humanoid = hit.Parent:findFirstChild("Zombie")
	Linez.Part = Tool.Electric
	Linez.Parent = target

end

barb:Remove()

elseif hit.CanCollide == true then
	barb:Remove()
end
end

function DriveStun(hit)
if hit.Parent:findFirstChild("Humanoid") or hit.Parent:findFirstChild("Zombie") ~= nil then
local s = script.Parent.DriveStunScript:clone()
s.Parent = hit.Parent
s.Disabled = false
end
end

function GetElectricTexture()
	local r = math.random(1,#electrictextures)
	return electrictextures[r]
end

function onButton1Down(mouse)
	mousedown = true
	if not enabled then
		return
	end
	if not enabled2 then return end
	enabled = false
	enabled2 = false

	if mouse.Hit ~= nil then
	mtarg = mouse.Hit.p
	end

	if cart and benabled then
	benabled = false
	Tool.Deployed.Value = true
	local v = (mtarg - Tool.Cart.Position).unit
	local v2 = ((mtarg + Vector3.new(0,-1.5,0)) - Tool.Cart.Position).unit

	local spawnPos = script.Parent.Cart.Position
	spawnPos  = spawnPos + (v * 2)

	Tool.BlastDoor1.Transparency = 1
	Tool.BlastDoor2.Transparency = 1

	local barb_1 = Instance.new("Part")

	barb_1.Position = spawnPos
	barb_1.FormFactor = 3
	barb_1.Size = Vector3.new(1,1,1)
	barb_1.Velocity = v * 500--1000
	barb_1.BrickColor = BrickColor.new(194)
	barb_1.BottomSurface = 0
	barb_1.TopSurface = 0
	barb_1.Name = "TaserBarb"
	barb_1.Elasticity = 0
	barb_1.Reflectance = 0.1
	barb_1.Friction = 1
	Tool.BarbMesh:clone().Parent = barb_1


	local sc = Tool.BarbScript:clone()
	sc.Parent = barb_1
	sc.Disabled = false

	local force = Instance.new("BodyForce")
	force.force = Vector3.new(0,150,0)
	force.Parent = barb_1

	barb_1.Parent = game.Workspace

	local barb_2 = barb_1:clone()
	barb_2.Position = spawnPos + (v2 * 2) + Vector3.new(0,-0.5,0)
	barb_2.Velocity = v2 * 500
	barb_2.BodyForce.force = Vector3.new(0,150,0)
	barb_2.Parent = game.Workspace

	barb_1.Touched:connect(function(hit) BarbTouched(hit, barb_1) end)
	barb_2.Touched:connect(function(hit) BarbTouched(hit, barb_2) end)
	Tool.Handle.Shot:Play()

	local al = 70 * (autolength / 5) + 2
	local t = 0
	local timerval = 0

	coroutine.resume(coroutine.create(function()
		while not enabled do
			t = t + 0.1
			if t < autolength then
			Tool.TimerVal.Value = math.ceil(autolength - t)
			else
			Tool.TimerVal.Value = math.ceil(t)
			end
			wait(0.1)
		end
		Tool.TimerVal.Value = 0
		end))

	while (mousedown or t < autolength  - 0.2) and not safety and t < 90 do
		script.Parent.Handle.sound:Play()
		script.Parent.Handle.sound2:Play()
		script.Parent.Handle.sound3:Play()
		wait(0.06)
	end

	if target ~= nil then
		if target:findFirstChild("OverrideScript") ~= nil then target.OverrideScript:Remove() end
	end

	Tool.TimerVal.Value = 0
	safety = false
	enabled = true
	wait(0.2)
	enabled2 = true

	elseif cart and target ~= nil then

	enabled = false
	local st = script.Parent.OverrideScript:clone()
	st.Disabled = false
	st.Parent = target

	local al = 70 * (autolength / 5) + 2
	local t = 0
	local timerval = 0

	coroutine.resume(coroutine.create(function()
		while not enabled do
			t = t + 0.1
			if t < autolength then
			Tool.TimerVal.Value = math.ceil(autolength - t)
			else
			Tool.TimerVal.Value = math.ceil(t)
			end
			wait(0.1)
		end
		Tool.TimerVal.Value = 0
		end))

	while (mousedown or t < autolength  - 0.2) and not safety and t < 90 do
		script.Parent.Handle.sound:Play()
		script.Parent.Handle.sound2:Play()
		script.Parent.Handle.sound3:Play()
		wait(0.06)
	end

	if target ~= nil then
		if target:findFirstChild("OverrideScript") ~= nil then target.OverrideScript:Remove() end
	end

	Tool.TimerVal.Value = 0
	safety = false
	enabled = true
	wait(0.2)
	enabled2 = true

	elseif not cart then

	enabled = false
	local con2 = script.Parent.Cart.Touched:connect(DriveStun)

	local al = 70 * (autolength / 5) + 2
	local t = 0

	coroutine.resume(coroutine.create(function()
		while not enabled do
			t = t + 0.1
			if t < autolength then
			Tool.TimerVal.Value = math.ceil(autolength - t)
			else
			Tool.TimerVal.Value = math.ceil(t)
			end
			wait(0.1)
		end
		Tool.TimerVal.Value = 0
		end))

	while (mousedown or t < autolength  - 0.2) and not safety and t < 90 do
		Tool.Electric.Decal.Texture = GetElectricTexture()
		script.Parent.Handle.sound:Play()
		script.Parent.Handle.sound2:Play()
		script.Parent.Handle.sound3:Play()
		wait(0.06)
	end

	Tool.Electric.Decal.Texture = ""
	con2:disconnect()

	Tool.TimerVal.Value = 0
	safety = false
	enabled = true
	wait(0.2)
	enabled2 = true
	else
	enabled = true
	enabled2 = true
	end
end

function onButton1Up(mouse)
	mousedown = false
end

function UpdateDisplay()
	if pgui == nil then return end
	if Tool.TimerVal.Value == 0 then
		pgui.Main.Countdown.Text = ""
	else
		pgui.Main.Countdown.Text = Tool.TimerVal.Value
	end
	if Tool.Cartr.Value == false then
		pgui.Main.CartStatus.BackgroundColor3 = Color3.new(255,255,255)
		pgui.Main.CartStatus.BorderColor3 = Color3.new(255,255,255)
		pgui.Main.CartStatus.Text = "-"
	elseif Tool.Deployed.Value == true then
		pgui.Main.CartStatus.BackgroundColor3 = Color3.new(255,255,255)
		pgui.Main.CartStatus.BorderColor3 = Color3.new(255,0,0)
		pgui.Main.CartStatus.Text = "X"
	else
		pgui.Main.CartStatus.BackgroundColor3 = Color3.new(255,255,255)
		pgui.Main.CartStatus.BorderColor3 = Color3.new(255,255,255)
		pgui.Main.CartStatus.Text = "1"
	end
end

function onKeyDown(key)
	if key == "y" and Tool.Lamp.Light.Enabled == true then
		Tool.Lamp.Light.Enabled = false
	elseif key == "y" then
		Tool.Lamp.Light.Enabled = true
	end
	if key == "r" and not enabled then
		safety = true
	elseif key == "r" and cart then
		cart = false
		Tool.Cartr.Value = false
		Tool.Cart.Transparency = 1
		Tool.Cart.CanCollide = false
		Tool.CartPart1.Transparency = 1
		Tool.CartPart1.CanCollide = false
		Tool.CartPart2.Transparency = 1
		Tool.CartPart2.CanCollide = false
		Tool.BlastDoor1.Transparency = 1
		Tool.BlastDoor1.CanCollide = false
		Tool.BlastDoor2.Transparency = 1
		Tool.BlastDoor2.CanCollide = false
		if Tool.LineV.Value == true then
		target:FindFirstChild("strings"):remove()
		Tool.LineV.Value = false
			end
	elseif key == "r" then
		Tool.Cartr.Value = true
		Tool.Deployed.Value = false
		cart = true
		benabled = true
		target = nil
		Tool.Cart.Transparency = 0
		Tool.Cart.CanCollide = true
		Tool.CartPart1.Transparency = 0
		Tool.CartPart1.CanCollide = true
		Tool.CartPart2.Transparency = 0
		Tool.CartPart2.CanCollide = true
		Tool.BlastDoor1.Transparency = 0
		Tool.BlastDoor1.CanCollide = true
		Tool.BlastDoor2.Transparency = 0
		Tool.BlastDoor2.CanCollide = true
		if Tool.LineV.Value == true then
		target:FindFirstChild("strings"):remove()
		Tool.LineV.Value = false
			end
	end
end

function onEquippedLocal(mouse)

	if mouse == nil then
		print("Mouse not found")
		return
	end

	local h = Tool.Parent:findFirstChild("Humanoid")

	if h~=nil and game.Players:findFirstChild(h.Parent.Name)~=nil then
	local gui = Tool.Gui:clone()
	gui.Parent = game.Players:findFirstChild(h.Parent.Name).PlayerGui
	pgui = gui

	UpdateDisplay()

	Tool.TimerVal.Changed:connect(UpdateDisplay)
	Tool.Cartr.Changed:connect(UpdateDisplay)
	Tool.Deployed.Changed:connect(UpdateDisplay)
	end

	mouse.Icon = "http://www.roblox.com/asset/?id=2966012"
	mouse.Button1Down:connect(function() onButton1Down(mouse) end)
	mouse.Button1Up:connect(function() onButton1Up(mouse)end)
	mouse.KeyDown:connect(onKeyDown)
end


Tool.Equipped:connect(onEquippedLocal)

function onUnequippedLocal()
			if Tool.LineV.Value == true then
		target:FindFirstChild("strings"):remove()
		Tool.LineV.Value = false
			end

	if pgui ~= nil then
		pgui:Remove()
		pgui = nil
	end
	if target ~= nil then
		if target:findFirstChild("OverrideScript") ~= nil then target.OverrideScript:Remove() end
	end
end

Tool.Unequipped:connect(onUnequippedLocal)