尝试比较 lua 的字符串和数字类型

script.Parent.Yes.MouseButton1Click:connect(function()
    if game.Players.LocalPlayer.leaderstats.Stage.Value < 20 and db then
        db = false
        script.Parent.Question.Text = "你需要至少完成20个阶段才能重生！"
        wait(3)
        script.Parent.Visible = false
        open = false
        db = true
    elseif db then
        game.ReplicatedStorage.Rebirth:FireServer()
        script.Parent.Visible = false
        open = false
    end
end)

为什么第2行会报错，提示尝试比较字符串和数字类型？