How to pause the game ?

Hello ,

I am developing a game that has a paralaxer scrolling , a main character and enemies and other things.
I have added all of those to game layer. Now I want to put a pause button and pause and also resume to resume the game.

Also can I use the same object to show different images ,this might be useful for the pause and resume to be changed depending on the condition.

Thankyou very much for the framework.