Change walkspeed on touched event?

Ok so basically i made a teleporting pad and rigged up with it is a gui that would cover the player's screen while teleporting, and i also want make it so the player can't move , i've tried but for some reason it just won't work

Here's the code

local tpTo = "TP2"
local Players = game:GetService('Players')

script.Parent.Touched:connect(function (hit)
        if hit.Parent:FindFirstChild('Humanoid') then
            local char = hit.Parent

            if Players:FindFirstChild(char.Name) then

                local plr = Players:FindFirstChild(char.Name)
                local gui = plr.PlayerGui.questchat.Teleport
                local human = hit.Parent.Humanoid

                gui:TweenSize(UDim2.new(1,0,1,0),Enum.EasingDirection.Out,Enum.EasingStyle.Quint,0.25)

        wait(0.25)

             if script.Parent.Locked == false and script.Parent.Parent:FindFirstChild(tpTo).Locked == false then

                script.Parent.Locked = true
                script.Parent.Parent:FindFirstChild(tpTo).Locked = true
                local pos = script.Parent.Parent:FindFirstChild(tpTo)
                human.WalkSpeed = 0
                char:moveTo(pos.Position)   
                script.Parent.Locked = false
                script.Parent.Parent:FindFirstChild(tpTo).Locked = false        
            end

                gui:TweenSize(UDim2.new(0,0,0,0),Enum.EasingDirection.In,Enum.EasingStyle.Quint,1)
                human.WalkSpeed = 16

            end 
        end 
end)