Answer 1

audio is a class
so you need to write
var audio= new Audio() and not
var audio=new audio()

notice A is in caps ..

Aside : and if you wish you can also combine play/pause in one function . Just like this : https://code.sololearn.com/Wjm8oXh7F7Gd/?ref=app

Answer 2

xD
you're welcome...