How do i make a forcefield block?

I want to make a block where whenever your touching it, it gives you a forcefield but when you get off of the block it goes away, this is my code

local forcePart = script.Parent

local canActivate = true



local function forceField(otherPart)

    local humanoid = otherPart.Parent:FindFirstChild('Humanoid')

    if humanoid and canActivate then

        canActivate = false

        forcePart.Transparency = 1

        forcePart.CanCollide = false

        local force = Instance.new('ForceField')

        force.Parent = humanoid.Parent

        wait(5)

        forcePart.Transparency = 0

        forcePart.CanCollide = true

        force:Destroy()

        canActivate = true

    end

end



forcePart.Touched:Connect(forceField)