How do I get rid of the pop-up window when I hit return?

I have just created a new document, and every time I press return a pop-up window appears asking me to select options from a drop down menu including ‘scene heading’ ‘action’ ‘character’ ‘parenthetical’ etc.

If anyone can advise how I can get rid of this pop up window I’d be really grateful!

The doc you are editing must be in script mode.
Do ‘Format/Scriptwriting/Script Mode’ to toggle out of this mode.

thanks so much - would never have worked that out!