Need help with functions?

Ok so Here is a working script

local NintendoToSega = game.Players.LocalPlayer.PlayerGui.ChooseCharacter.NintendoToSega

function onClick4() if NintendoToSega.Visible then NintendoToSega.Visible = false end end

button.MouseButton1Click:connect(onClick4)

I need to know A way to write it If it is not visible it will be visible because I have tried

local SegaToNintendo = game.Players.LocalPlayer.PlayerGui.ChooseCharacter.SegaToNintendo

function onClick5() if SegaToNintendo.Visible = false then SegaToNintendo.Visible end end

button.MouseButton1Click(onClick5)

And Then there is a red line under = for "= false" Please Help