I understand the basic way to do the CFrame would be:

function movingblocks(onClick)
	part.CFrame = part.CFrame + CFrame.new(0, .1, 0)
	wait(1)
	part.CFrame = part.CFrame + CFrame.new(0, -.1, 0)
end

but how would it to return on the second click so that the wait(1) doesnt have to be there