Script isn't playing animations, what's wrong?

So this is the script;

User = game.Players.LocalPlayer
UserMouse = User:GetMouse()

Animation = Instance.new("Animation")
Animation.AnimationId = "http://www.roblox.com/Asset?ID=190972547"
Animation.Name = "BackFlip"
animTrack = User.Character.Humanoid:LoadAnimation(Animation)

UserMouse.KeyDown:connect(function(key) -- keydown function
    if key == "q" then 
    animTrack:Play()
    end
end)

I'm confused what's the problem?....