Basic script doesn't work in Play mode?

Whenever I go to Play Solo mode, the script works, but when I click Play, it doesn't work. Why?

H = game.Workspace.Door

function onTouch(Door)
H.Transparency = 0.5
H.CanCollide = false
wait(5)
H.Transparency = 0
H.CanCollide = true
end

script.Parent.Touched:connect(onTouch)