How do you change the asset id of an animation in the "Animate" local script?

I copied the "Animate" local script and pasted it into the startercharacterscripts. I wanted to have an animation where the run and walk animations are different, so I did this. By the way I am using r15, r15 uses the "run" animation.

Script:

local Character = script.Parent
local Humanoid = Character:WaitForChild("Humanoid")
local pose = "Standing"
local userinput = game:GetService("UserInputService")
walkorrun = nil

userinput.InputBegan:Connect(function(input, gameprocess) 
    if not gameprocess then
        if not input.KeyCode == Enum.KeyCode.LeftShift then
            walkorrun = "http://www.roblox.com/asset/?id=7332952929"
            script.run.RunAnim.AnimationId = "rbxassetid://7332952929"
        end
        if input.KeyCode == Enum.KeyCode.LeftShift then
            walkorrun = "http://www.roblox.com/asset/?id=7379382873"
            script.run.RunAnim.AnimationId = "rbxassetid://7379382873"
        end
    end
end)



local userNoUpdateOnLoopSuccess, userNoUpdateOnLoopValue = pcall(function() return UserSettings():IsUserFeatureEnabled("UserNoUpdateOnLoop") end)
local userNoUpdateOnLoop = userNoUpdateOnLoopSuccess and userNoUpdateOnLoopValue

local userEmoteToRunThresholdChange do
    local success, value = pcall(function()
        return UserSettings():IsUserFeatureEnabled("UserEmoteToRunThresholdChange")
    end)
    userEmoteToRunThresholdChange = success and value
end

local userPlayEmoteByIdAnimTrackReturn do
    local success, value = pcall(function()
        return UserSettings():IsUserFeatureEnabled("UserPlayEmoteByIdAnimTrackReturn2")
    end)
    userPlayEmoteByIdAnimTrackReturn = success and value
end

local AnimationSpeedDampeningObject = script:FindFirstChild("ScaleDampeningPercent")
local HumanoidHipHeight = 2

local EMOTE_TRANSITION_TIME = 0.1

local currentAnim = ""
local currentAnimInstance = nil
local currentAnimTrack = nil
local currentAnimKeyframeHandler = nil
local currentAnimSpeed = 1.0

local runAnimTrack = nil
local runAnimKeyframeHandler = nil

local PreloadedAnims = {}

local animTable = {}
local animNames = { 
    idle =  {   
                { id = "http://www.roblox.com/asset/?id=507766666", weight = 1 },
                { id = "http://www.roblox.com/asset/?id=507766951", weight = 1 },
                { id = "http://www.roblox.com/asset/?id=507766388", weight = 9 }
            },
    walk =  {   
        { id = "http://www.roblox.com/asset/?id=7332952929", weight = 10 } 
            }, 
    run =   {
        { id = walkorrun, weight = 10 } -- I put the "walkorrun" variable here
            }, 

The problem is it's not working, the animation is not applying and the legs of my character just freezes. Is there another way to do this?