Door script help?

So I have a door script. It's suppose to like every 5 seconds it's transparency 0.5 then 5 seconds later 0. At the same time. the ConCollide is true, then false. At the same time.

while true do
	game.Workspace.Door.Transparency=0.5
	wait(5)
	game.Workspace.Door.Transparency=0
	wait(5)
end
while true do
	game.Workspace.Door.CanCollide = true
	wait(5)
	game.Workspace.Door.CanCollide = false
	wait(5)
end

Door = game.Workspace.Door
while true do
    Door.Transparency=0.5
    Door.CanCollide = true
    wait(5)
    Door.Transparency = 0
    Door.CanCollide = false
    wait(5)
end

This is the correct script, I think you got mixed up.