Just real simple, but something that is very useful to know, for reusability purposes or for whatever you may think of.
Steps
Import a sound into your library.
Right click the sound and select linkage then check, Export for actionscripting and Export in first frame
Then in your first frame put
s = new Sound();//declare s as a sound
s.attachSound("buttonSound");//attach the linked sound 'buttonSound' to s
myButton.onRollOver=function(){// make a function
s.stop();//and just so we dont get
//that aweful looping over one sound, we will stop
//it before we start it again.
s.start();//starts the sound
}
This creates a sound object 's' and puts your sound file named 'buttonSound' into 's'. Then creates a function so that when you roll over the button it plays the sound, pretty straight