How do I make a bayonet script?

I was trying to make a gun with a bayonet and i wanted it to do damage, the script I have in it is called "BayonetScript"

r = game:service("RunService")


local damage = 7


local slash_damage = 15
local lunge_damage = 45

sword = script.Parent.Handle
Tool = script.Parent


local SlashSound = Instance.new("Sound")
SlashSound.SoundId = "rbxasset://sounds\\swordslash.wav"
SlashSound.Parent = sword
SlashSound.Volume = .7

local LungeSound = Instance.new("Sound")
LungeSound.SoundId = "rbxasset://sounds\\swordlunge.wav"
LungeSound.Parent = sword
LungeSound.Volume = .6

local UnsheathSound = Instance.new("Sound")
UnsheathSound.SoundId = "rbxasset://sounds\\unsheath.wav"
UnsheathSound.Parent = sword
UnsheathSound.Volume = 1

function DarkKill(character, humanoid, attacker)

    if (character:FindFirstChild("ForceField") ~= nil) then return end

    local childs = character:GetChildren()

    local colors = {}

    tagHumanoid(humanoid, attacker)
    humanoid.Health = 0

    for i=1,#childs do
        if (childs[i].className == "Part") then
            colors[i] = childs[i].BrickColor
            childs[i].BrickColor = BrickColor.new(26)
            childs[i].CanCollide = true
            childs[i].Anchored = true
        end
    end

    wait(.25)

    for i=1,#childs do
        if (childs[i].className == "Part") then
            local b = Instance.new("BodyVelocity")
            b.velocity = Vector3.new(math.random() - .5, 0, math.random() - .5).unit * 80
            b.maxForce = Vector3.new(1e5,1e5,1e5)
            b.Parent = childs[i]
        end
    end

    for i=1,#childs do
        if (childs[i].className == "Part") then
            childs[i].Anchored = false
        end
    end








end




function blow(hit)
    local humanoid = hit.Parent:findFirstChild("Monster")
    local vCharacter = Tool.Parent
    local vPlayer = game.Players:playerFromCharacter(vCharacter)
    local hum = vCharacter:findFirstChild("Humanoid") -- non-nil if tool held by a character
    if humanoid~=nil and humanoid ~= hum and hum ~= nil then
        -- final check, make sure sword is in-hand

        local right_arm = vCharacter:FindFirstChild("Right Arm")
        if (right_arm ~= nil) then
            local joint = right_arm:FindFirstChild("RightGrip")
            if (joint ~= nil and (joint.Part0 == sword or joint.Part1 == sword)) then
                hum.Health = hum.Health + (damage * .5)
                if humanoid.Health > damage then
                    tagHumanoid(humanoid, vPlayer)
                    humanoid:TakeDamage(damage)
                    wait(1)
                    untagHumanoid(humanoid)
                else
                    DarkKill(humanoid.Parent, humanoid, vPlayer)
                end
            end
        end


    end
end



function tagHumanoid(humanoid, player)
    local creator_tag = Instance.new("ObjectValue")
    creator_tag.Value = player
    creator_tag.Name = "creator"
    creator_tag.Parent = humanoid
end

function untagHumanoid(humanoid)
    if humanoid ~= nil then
        local tag = humanoid:findFirstChild("creator")
        if tag ~= nil then
            tag.Parent = nil
        end
    end
end


function attack()
    damage = slash_damage
    SlashSound:play()
    local anim = Instance.new("StringValue")
    anim.Name = "toolanim"
    anim.Value = "Slash"
    anim.Parent = Tool
end

function lunge()
    damage = lunge_damage

    LungeSound:play()

    local anim = Instance.new("StringValue")
    anim.Name = "toolanim"
    anim.Value = "Lunge"
    anim.Parent = Tool


    force = Instance.new("BodyVelocity")
    force.velocity = Vector3.new(0,10,0) --Tool.Parent.Torso.CFrame.lookVector * 80
    force.Parent = Tool.Parent.Torso
    wait(.25)
    swordOut()
    wait(.25)
    force.Parent = nil
    wait(.5)
    swordUp()

    damage = slash_damage
end

function swordUp()
    Tool.GripForward = Vector3.new(-1,0,0)
    Tool.GripRight = Vector3.new(0,1,0)
    Tool.GripUp = Vector3.new(0,0,1)
end

function swordOut()
    Tool.GripForward = Vector3.new(0,0,1)
    Tool.GripRight = Vector3.new(0,-1,0)
    Tool.GripUp = Vector3.new(-1,0,0)
end

function swordAcross()
    -- parry
end


Tool.Enabled = true
local last_attack = 0
function onActivated()

    if not Tool.Enabled then
        return
    end

    Tool.Enabled = false

    local character = Tool.Parent;
    local humanoid = character.Humanoid
    if humanoid == nil then
        print("Humanoid not found")
        return 
    end

    t = r.Stepped:wait()

    if (t - last_attack < .2) then
        lunge()
    else
        attack()
    end

    last_attack = t

    --wait(.5)

    Tool.Enabled = true
end


function onEquipped()
    UnsheathSound:play()
end


script.Parent.Activated:connect(onActivated)
script.Parent.Equipped:connect(onEquipped)


connection = sword.Touched:connect(blow)