How do I set my android app to landscape mode entirely?

Hi guys, I would love to know how to make my app that I am making in landscape mode only so that it loads up like that on start and wont revert to portrait orientation when the phone is flipped.

I found this code.

**function Start () {

Screen.orientation = ScreenOrientation.LandscapeLeft; }**

Will this work and where do I apply the script to?

Thanks!