Weapon problem, still not working?

Is this right? Someone helped me earlier which i greatly was happy for but i did not quite understand. Is this right? If not please fix it, thanks!

local SlashDamage = 25
local DownStabDamage = 25
local RegularDamage = 25
local ThrowSpeed = 85
local LaunchSpeed = 0.38

function Start()
if Game.Players.LocalPlayer.PlayerGui.Default.Value == true then
    SlashDamage = 25
    DownStabDamage = 25
    RegularDamage = 25
    ThrowSpeed = 85
    LaunchSpeed = 0.38
    return Start
end
if Game.Players.LocalPlayer.PlayerGui.Upgrade2.Value == true then
    SlashDamage = 35
    return Start
end
if Game.Players.LocalPlayer.PlayerGui.Upgrade3.Value == true then
    DownStabDamage = 35
    return Start
end
if Game.Players.LocalPlayer.PlayerGui.Upgrade4.Value == true then
    RegularDamage = 35
    return Start
end
if Game.Players.LocalPlayer.PlayerGui.Upgrade5.Value == true then
    ThrowSpeed = 100
    SlashDamage = 50
    DownStabDamage = 50
    RegularDamage = 50
    return Start
end
if Game.Players.LocalPlayer.PlayerGui.Upgrade6.Value == true then
    ThrowSpeed = 125
    return Start
end
if Game.Players.LocalPlayer.PlayerGui.Upgrade7.Value == true then
    LaunchSpeed = 0.19
    return Start
end
end