package
{
    public class Model extends
    {
        public static const SOUND_ON:String = "sound.volume.on";
        public static const SOUND_OFF:String = "sound.volume.off";

        private static var instance:Model;

        private var _soundVolume:String = SOUND_ON;

        public static function getInstance():Model
        {
            if (Model.instance == null) Model.instance = new Model();
            return Model.instance;
        }

        public function get soundVolume():String
        {
            return _soundVolume;
        }

        public function set soundVolume( v:String ):void
        {
            _soundVolume = v;
        }
    }
}

package
{
    import src.clientname.Model;
    import flash.display.*;

    public class View extends Sprite
    {
        public function View()
        {
            // set sound off
            Model.getInstance().soundVolume = Model.SOUND_OFF;

            // set sound on
            Model.getInstance().soundVolume = Model.SOUND_ON
        }
    }
}