different actions on one button

How do I...?
1

I have a button and I made it so that when I click on it, another layer is shown, but how can I make it so that when I click the same button, the layer is hidden again?

2

Make number variable
Call it for example Switcher
Now make event

Condition
Button is clicked
Trigger once

Action
Change value of Switcher ADD 1
Change value of Switcher SET TO mod(Switcher,2)

Now make 2 events
Condition
Switcher value = 0

Action
Show Layer

Condition
Switcher value = 1

Action
Hide Layer