package  {
   
  import flash.events.KeyboardEvent;
  import flash.events.Event;
  import flash.display.Stage;
  import flash.ui.Keyboard;
  import flash.display.MovieClip;
   
  public class KeyboardTank extends MovieClip {

   public var keyPressed:uint;
   public var rightKeyIsDown:Boolean;
   public var leftKeyIsDown:Boolean;
      public var speed:Number = 5;
    
   public function KeyboardTank():void {
    // constructor code
   rightKeyIsDown = false;
   leftKeyIsDown = false;
    
     this.addEventListener(KeyboardEvent.KEY_DOWN,pressKey);
  this.addEventListener(KeyboardEvent.KEY_UP,releaseKey);
  this.addEventListener(Event.ENTER_FRAME,moveTank);
  }
  public function pressKey(e:KeyboardEvent):void{
   keyPressed = e.keyCode;
   if(keyPressed == Keyboard.D){
    rightKeyIsDown = true;
   }
         if(keyPressed == Keyboard.A){
    leftKeyIsDown = true;
   }
   
  }
  public function releaseKey(e:KeyboardEvent):void{
   var thisKey:uint = e.keyCode;
   if(thisKey == Keyboard.D){
    rightKeyIsDown = false;
   }
      if(thisKey == Keyboard.A){
    leftKeyIsDown = false;
   }
  }
  public function moveTank(e:Event):void{
   if(rightKeyIsDown){
    this.x += speed;
   }
   if(leftKeyIsDown){
    this.x -= speed;
   }
  }
  }
  }

public class Tank extends MovieClip

public class Tank extends KeyboardTank