Flash CS3 Play/Stop audio button problem

You should consider using the Sound class. Here's a quick overview of it:

http://help.adobe.com/en_US/as3/dev/WS5b3ccc516d4fbf351e63e3d118a9b90204-7d21.html

You'll be able to add event listeners to the sound to know when it completes so you can execute more code, such as swapping the play and stop button. There is an example in that overview of listening for the SOUND_COMPLETE event (e.g. channel.addEventListener(Event.SOUND_COMPLETE, onPlaybackComplete);). It should contain everything you need.

A basic example of what you'll end up with (there's many ways to do it) might look something like this:

// just set up and wait for click var isPlaying:Boolean = false; var mySound:Sound = new MySoundInLibrary(); var myChannel:SoundChannel = new SoundChannel(); myChannel.addEventListener(Event.SOUND_COMPLETE, onPlaybackComplete); // buttons play_btn.addEventListener(MouseEvent.CLICK,clickhandler); stop_btn.addEventListener(MouseEvent.CLICK,clickhandler); function clickhandler(event:MouseEvent):void {             swapChildren(play_btn, stop_btn);             if (isPlaying)           {                     isPlaying = false;                     myChannel.stop();           }           else           {                     isPlaying = true;                     myChannel = mySound.play();           } } function onPlaybackComplete(e:Event):void {           isPlaying = false;           swapChildren(play_btn, stop_btn); }

The basic idea is keeping a flag if the audio is currently playing. If it isn't then assign the sound to a channel and play it while setting the flag (isPlaying) to true. If it's already playing, set the flag to false and stop playing the audio.

The swapChildren is run in the onPlaybackComplete() method so when the audio completes the play button is swapped back in front.

Rather than swapping the children I'd urge you to toggle the .visible property instead. It's easy to run commands in the wrong order and get desynched on depth.