What should I do?

Here are the scripts:

Frame = ScreenGui.MainMenu

function onClicked()
    for k, p in pairs(game.Players:GetPlayers()) do
        p.PlayerGui.Frame.Visible=false
    end
end

script.Parent.MouseButton1Click:connect(onClicked)

Frame = ScreenGui.GameInfo

function onClicked()
    for k, p in pairs(game.Players:GetPlayers()) do
        p.PlayerGui.Frame.Visible=true
    end
end

script.Parent.MouseButton1Click:connect(onClicked)

Appears a message: Players.Player1.PlayerGui.ScreenGui.MainMenu.Frame.Informat:1: attempt to index global 'ScreenGui' (a nil value) and Players.Player1.PlayerGui.ScreenGui.MainMenu.Frame.Informat:1: attempt to index global 'ScreenGui' (a nil value). I don't know what will I do, is this?


game.StarterGui.ScreenGui:ChangeThingToValue(function()

Or this?


Frame.Visible:ChangeToAnotherFrameTheCurrentValue = true

Scripting is so hard for me...