Name button instances
You'll provide instance names for the buttons on the Stage so that you can refer to the instance names in ActionScript.
- On the main Timeline, select the Content layer.
- On the lower-right side of the Stage, select the button at the left. In the Property inspector (Window > Properties), type goScene_btn in the Instance Name text box to name the instance of the symbol.

- Select the middle button and use the Property inspector to give the button an instance name of attachMovie_btn.
- Select the far right button and use the Property inspector to give the button an instance name of playSound_btn.