Menu Error (Please Help)?

I have a script I've made that is suppose to change the font and size of my GUI button when entered and revert it back to it's original size when out of the buttons perimeter, for some reason it's not working like I thought it would be, any answers?

Player = game.Players.LocalPlayer
Menu = script.Parent
Play = Menu.Play
about = Menu.About

function MouseEnterPlayButton()
    Play.FontSize = "Size42"
    Play.Size = UDim2.new(0.45, 0, 0.225, 1000)
end

function MouseLeftPlayButton()
    --166, 166, 166
    Play.FontSize = "Size32"
    Play.Size = UDim2.new(0.3, 0, 0.15, 0)
end

Play.MouseEnter:connect(MouseLeftPlayButton)
Play.MouseEnter:connect(MouseEnterPlayButton)