Stop sound when input text field is empty

programming flash
1

when somebody backspaces a clicking noise happens, and when the field is empty I want the noise to stop while they are still pressing backspace. Any ideas? (I’m still kinda a noob at scripting=)) But the solution should not be so difficult to identify.

Code:

var backSpace:Sound = new Sound();
var myChannel:SoundChannel = new SoundChannel();
backSpace.load(new URLRequest(“Sounds-Music/backSpace.mp3”));

…

if(textBox.length == 0){
myChannel.stop();

}