tried to do script that activates himself when player touches another block but Script Not Working?

wait(0.5)
repeat wait() until game.Workspace:FindFirstChild("Trigger") == nil
while true do
    wait(1)
    for i = 1, 70 do
        script.Parent.CFrame = script.Parent.CFrame * CFrame.new(0, 0, 0.3)
        wait(0.001)
    end
    wait(4)
    for i = 1, 70 do
        script.Parent.CFrame = script.Parent.CFrame * CFrame.new(0, 0, -0.3)
        wait(0.001)


    end
end