Problems setting the volume to a sound object.Plz help me!

programming flash
1

Hi!

I am trying to make a volume control in my flash movie with actionscript 2.0

Here is my code:


var s : Sound = new Sound();
var volPos : Number = 20;

s.setVolume(volPos);

btBaixa.onRelease = function()
{
    if(volPos > 0){
     volPos -= 10;
    }
    s.setVolume(volPos);
}

btAumenta.onRelease = function()
{
    if(volPos < 100){
     volPos += 10;
    }
    s.setVolume(volPos);
}

but the problem is the first time I lanch my movie it comes in a good volume.As soon as I hit the up or down button to lower or increase the volume firts the volume goes down a lot and then starts to increase or decrease its volume.

What is wrong with it?