How Do I Make This Punching Animation Button Do Damage When It's Played?

Punch button script:

local animation = Instance.new ("Animation")

animation.AnimationId = "http://www.roblox.com/Asset?ID=2837975148"

  

local trackanimation = nil

local canplay = true

function playAnimation(AnimationSouce)

if canplay == true then

local plr = game.Players.LocalPlayer

trackanimation = plr.Character.Humanoid:LoadAnimation(animation)

  

trackanimation.KeyframeReached:connect(function()

end)

trackanimation:Play()

end

end

script.Parent.MouseButton1Click:connect(playAnimation)