[GUI] Why Doesnt This Work?

Trying to make a Level Up Bar

 player = game.Players.LocalPlayer
while true do
    wait()
if player.Level.Value >= 10 then
    script.Parent:TweenSizeAndPosition(UDim2.new(0, 50,0, 75), UDim2.new(0, 675,0, 475), "Out", "Quad", 1) 
end
if player.Level.Value >= 20 then
    script.Parent:TweenSizeAndPosition(UDim2.new(0,150,0, 75), UDim2.new(0, 675,0, 475), "Out", "Quad", 1) 
end
end