My experience and level system won't work?

So I'm making an experience system. The user gains experience but they never level up.

code -

game.Players.PlayerAdded:connect(function(player)

wait(4)

    xp = player.savedvalues.xp
    level = player.savedvalues.level

    level1xp = 0 --first level
    level2xp = 50 --second level
    level3xp = 100 --third level
    level4xp = 150 --fourth level
    level5xp = 200

    xp.Changed:connect(function()

        if xp.Value >= level1xp and xp.Value < level2xp then

            level.Value = 1

        elseif xp.Value >= level2xp and xp.Value < level3xp then

            level.Value = 2

        elseif xp.Value >= level3xp and xp.Value < level4xp then

            level.Value = 3

        elseif xp.Value >= level4xp and xp.Value < level5xp then

            level.Value = 4

        elseif xp.Value >= level5xp then

            level.Value = 5

        end

    end)
end)

Am I just missing something really obvious?

Thanks for reading