So i want to stop the animation when my character's walkspeed changes from 0, how?

local player = game.Players.LocalPlayer
repeat wait() until player.Character
local char = player.Character
local hum = char.Humanoid
local running = false
local UIS = game:GetService("UserInputService")
local ToggleSusan = game.ReplicatedStorage:WaitForChild("ToggleSusan")

UIS.InputBegan:Connect(function(Input, Chat)
	if Input.KeyCode == Enum.KeyCode.E and not Chat and hum.Health >= 1 then
		if running == false then
			ToggleSusan:FireServer(true)
			local Anim = Instance.new('Animation')
			Anim.AnimationId = script.Idle.AnimationId
			PlayAnim = char.Humanoid:LoadAnimation(Anim)
			PlayAnim:Play()
			
			running = true
		elseif running == true then
			ToggleSusan:FireServer(false)
			PlayAnim:Stop()
			running = false
		elseif running == true then
			
			if hum.walkspeed > 0 then
				
				PlayAnim:Stop()	
		end
		

				
			
		end
	end
end)

so this is what i did, u see and the buttom i tried it so when the Walkspeed is bigger than 0 the animation stop but it doesn't do anything any help is apreaciated