Animation Plays When Value hits 0?

Basically, I can't figure out how when a value hits 0, an animation loads into the player with the value that is 0. This is all I have for now, and yes the Animation is mine but it doesn't play.

local plr = script.Parent.Parent
local char=plr.CharacterAdded:wait()
local player=workspace:findFirstChild(plr.Name)
local humanoid = player.Character.Humanoid

while wait() do
    if plr.Ankles.Value <= 0 then
local anim = Instance.new("Animation")
anim.AnimationId = "http://www.roblox.com/asset/?id=529177665"
        local playAnim = humanoid:LoadAnimation(anim)
        playAnim:Play()
        script.Sound:Play()
            end
    plr.Ankles.Value=100 -- How many times do they have to get crossed for them to fall
end