Control Rectangle Opacity via Button

I am sure this is very easy but I am very new to Hype3 and javascript I want to be able to change the opacity of a rectangle via two buttons on to make to increase the opacity and one to decrease could someone please point me in the right direction.

Do you want to change the opacity gradually via a timeline or using javascript?

D (18.8 KB)

The simplest way is to use a timeline.

You can set the timeline to increments and have the buttons play it forward or in reverse. The timeline will pause at each increament (10.9 KB)