''Visible is not a valid member of ScreenGui'' What is this error?

script.Parent.MouseButton1Down:Connect(function() script.Parent.Parent.Visible = true end)

I am trying to do a Index Menu. It should go like this: There is a text button. I press it, the Index Menu opens.

But an error appears. It says ''Visible is not a valid member of IndexMENU(name of the screengui)

When I do script.Parent.MouseButton1Down:Connect(function() script.Parent.Parent.Visible = false end)

it works. But when I do ''true'' it doesn't

Please, help me somebody!

use enabled not visible