ActionScript 3.0 :: Stop Looping Stream Sound Imported From Library?

How do you tell flash to stop Looping a stream sound that is imported from the library via Linkage method into AS3? I understand the idea of soundChannel that control the sound.

PHP Code:
block_mc.addEventListener(Event.ENTER_FRAME, enterframe);
function enterframe(event:Event):void{
if(block_mc.hitTestObject(circle_mc)){
myChannel= mySound.play();
}else{
myChannel.stop();

The above is a drag and drop situation, so when the block_mc is no longer hitting the circle_mc, the sound echoes or loops multiple times before coming to a stop. Any clue how to rectify this. How do you use onSoundComplete in AS3.