How do I use the Duration property in a spawn location?

I want a game where you have a inf force field but when you are in the game, it goes away. Script:

script.Parent.Touched:Connect(function()
	game.Workspace.Spawn_Area.SpawnLocation.Duration = 0
end)

Nothing happens. Please help me. Thank you!

My script that puts you in game:

local seconds = game.Workspace.Time
local ingame = game.Workspace.InGame.Value
local Game = game.Workspace.Game.Position


while true do

	wait(1)
	seconds.Value = seconds.Value - 1

	if seconds.Value == 0 and ingame == 0 then

		ingame = 1
		seconds.Value = 30

		local teleport = game.Players:GetChildren()
		for i = 1, #teleport do
			teleport[i].Character:MoveTo(Vector3.new(Game.X, Game.Y, Game.Z))

		end
	end

	if seconds.Value == 0 and ingame == 1 then

		ingame = 0
		seconds.Value = 15

		local teleport = game.Players:GetChildren()
		for i = 1, #teleport do
			teleport[i]:LoadCharacter()

		end
	end


end