Toggle a JavaScript script

My issue is:

I have a grid display of some photos on my webpage, and I have a JavaScript script that transforms that grid into a slide-bar where you can navigate through that photos by clicking the arrows of the bar.

What I want is a button that allows the visitors to swap between the grid and the slide views (that is, a button to start/stop the execution of the script, right?).

I wonder if that is possible and how can that be done. I did not code the webpage nor the script, though.