Making a button open a window on a gui?

I'd probly do something like this;

script.Parent.MouseButton1Click:connect(function() --I use LocalScripts when it comes to the Players
--Gui
gui=script.Parent:FindFirstChild("Frame")
if gui~=0 then
gui.Visible=true
end end) --Something like that

If you do not understand still, then contact me and I'll see what I can do to help.

Like this;

gui = script.Parent.Button
frame = script.Parent.Frame

gui.MouseButton1Down:connect(function()
frame.Visible = not frame.Visible;
end)