Keyboard listener not making sense

programming flash
1

I’m trying to understand the keyboard listeners and make something that will bring up a dialogue box whenever someone types a specific phrase. This is my code:


package {
    import flash.display.Stage;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    //
    public class KeyLogger {
        private var keys:String = "";
        private var phrase:String = "pass";
        public function KeyLogger(stage:Stage):void {
            stage.addEventListener(KeyboardEvent.KEY_DOWN, keyReleased);
        }
        //
        private function keyReleased(e:KeyboardEvent):void {
            keys += String.fromCharCode(e.keyCode);

            if (keys == phrase) {
                   showBox();
            }

            trace(keys);
        }
        //
        private function showBox():void {
             //
        }
    }
}

The weird thing is the listener seems to be capturing key presses, but not all of them. I tried every letter a-z then the numbers on the keyboard and it only grabbed these:

DGUWX1234567890

Is there something I’m unaware of about these keys that would cause this?