Why does this script work in studio but not in-game?

So this is supposed to make my ImageLabel move up and down over and over, it works in studio, but not in-game. Here is the script:

while true do
    for i = 1,10 do
        wait()
        script.Parent.Position = script.Parent.Position + UDim2.new(0,0,.01,0)
    end
    wait(.25)
    for i = 1,10 do
        wait()
        script.Parent.Position = script.Parent.Position - UDim2.new(0,0,.01,0)
    end
end