1010: A term is undefined and has no properties.

Here is my update function not sure if it helps solve anything

private function update(evt:Event)

                    {

                              //******************z

                              //Handle User Input

                              //******************

                              //Handle Player 1 User Input

                              if (moveX > 0)

                              {

                                        if (player.x <= C.PLAYER_RIGHT_BOUND)

                                                  player.x += C.PLAYER_SPEED;

                              }

                              else if (moveX < 0)

                              {

                                        if (player.x > C.PLAYER_LEFT_BOUND)

                                                  player.x -= C.PLAYER_SPEED;

                              }

                              if (moveY > 0)

                              {

                                        if (player.y <= C.PLAYER_DOWN_BOUND)

                                                  player.y += C.PLAYER_SPEED;

                              }

                              else if (moveY < 0)

                              {

                                        if (player.y > C.PLAYER_UP_BOUND)

                                                  player.y -= C.PLAYER_SPEED;

                              }

                              //Handle Firing of bullets

                              if (fireBullet)

                              {

                                        var currTime = getTimer();

                                        if (currTime - lastBulletTime > C.BULLET_DELAY)

                                        {

                                                  lastBulletTime = currTime;

                                                  var newBullet = new Bullet(player.x, player.y);

                                                  bullets.push(newBullet);

                                                  mcGameStage.addChild(newBullet);

                                        }

                                        fireBullet = false;

                              }

                              //******************

                              //Handle Game Logic

                              //******************

                              //Check to spawn new enemies

                              if (Math.random() < C.SPAWN_ENEMY_CHANCE)

                              {

                                        //Create a new monster

                                        var newEnemy = new Enemy();

                                        enemies.push(newEnemy);

                                        mcGameStage.addChild(newEnemy);

                              }

                              //Update enemies

                              for (var i=enemies.length - 1; i >= 0; i--)

                              {

                                        enemies.update();

                              }

                              //Update bullets

                              for (var i=bullets.length - 1; i >= 0; i--)

                              {

                                        bullets.update();

                                        if (bullets.notInScreen())

                                        {

                                                  mcGameStage.removeChild(bullets);

                                                  bullets.splice(i,1);

                                        }

                              }

                              //Check for collision

                              //---------------------

                              //Bullet and Enemy collisions

                              for (var i=bullets.length - 1; i >= 0; i--)

                              {

                                        for (var j=enemies.length - 1; j >= 0; j--)

                                        {

                                                  if (bullets.hitTestObject(enemies.collisionArea))

                                                  {

                                                            //Increase player score

                                                            playerScore += enemies.getPointsWorth();

                                                            //Remove bullet and enemy

                                                            mcGameStage.removeChild(bullets);

                                                            mcGameStage.removeChild(enemies);

                                                            bullets.splice(i,1);

                                                            enemies.splice(j,1);

                                                            break;

                                                  }

                                        }

                              }

                              //Player and Enemy collisions

                              for (var j=enemies.length - 1; j >= 0; j--)

                              {

                                        if (player.collisionArea.hitTestObject(enemies.collisionArea))

                                        {

                                                  mcGameStage.removeChild(player);

                                                  mcGameStage.removeChild(enemies);

                                                  enemies.splice(j,1);

                                                  player = null;

                                                  gameOver();

                                                  break;

                                        }

                              }

                              //******************

                              //Handle Display

                              //******************

                              //Update scrolling of background image

                              mcBackground1.x -= C.SCROLL_SPEED;

                              mcBackground2.x -= C.SCROLL_SPEED;

                              if (mcBackground1.x <= -mcBackground1.width)

                              {

                                        //switch it to the back of background 2

                                        mcBackground1.x = mcBackground2.x + mcBackground2.width;

                              }

                              else if (mcBackground2.x <= -mcBackground2.width)

                              {

                                        //switch it to the back of background 1

                                        mcBackground2.x = mcBackground1.x + mcBackground1.width;

                              }

                              //Display new Score

                              txtScorePlayer.text = String(playerScore);

                    }