#1009: Cannot access a property or method of a null object reference.

this is my action script by the way, please take a look with this 🙂 and I used class with this one.

ps. this is a school project and needs to be done by Thursday 😞

var enterPressed: Boolean = false;
var spacePressed: Boolean = false;
var upPressed: Boolean;
var downPressed: Boolean;
var leftPressed: Boolean;
var rightPressed: Boolean;
var WPressed: Boolean;
var SPressed: Boolean;
var APressed: Boolean;
var DPressed: Boolean;
var shieldMax: int = 100;
var damage: int = 20;
var carshield1: Number = shieldMax;
var carshield2: Number = shieldMax;
var dot1: Dot1;
var dot2: Dot2;
var dot1Array: Array = new Array();
var dot1Ready: Boolean = false;
var dot2Array: Array = new Array();
var dot2Ready: Boolean = false;
const dotspeed: int = 20;
carmeter1.height = shieldMax;
carmeter2.height = shieldMax;
var endOfLife: Boolean = false;

car1.x = 276;
car1.y = 417;
car2.x = 361;
car2.y = 418;

stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyPress);
stage.addEventListener(KeyboardEvent.KEY_UP, onKeyRelease);
stage.addEventListener(Event.ENTER_FRAME, playGame);

car1.speed = 5;
car2.speed = 5;
car1.turning = 3;
car2.turning = 3;

function onKeyPress(e: KeyboardEvent): void {

if (e.keyCode == Keyboard.UP) {
upPressed = true;
}
if (e.keyCode == Keyboard.DOWN) {
downPressed = true;
}
if (e.keyCode == Keyboard.LEFT) {
leftPressed = true;
}
if (e.keyCode == Keyboard.RIGHT) {
rightPressed = true;
}
if (e.keyCode == Keyboard.W) {
WPressed = true;
}
if (e.keyCode == Keyboard.S) {
SPressed = true;
}
if (e.keyCode == Keyboard.A) {
APressed = true;
}
if (e.keyCode == Keyboard.D) {
DPressed = true;
}
if (e.keyCode == Keyboard.ENTER) {
enterPressed = true;
if (!dot2Ready) {
dot2 = new Dot2();
dot2Ready = true;
}
}
if (e.keyCode == Keyboard.SPACE) {
spacePressed = true;
if (!dot1Ready) {
dot1 = new Dot1();
dot1Ready = true;
}
}
}

function onKeyRelease(e: KeyboardEvent): void {
if (e.keyCode == Keyboard.UP) {
upPressed = false;
}
if (e.keyCode == Keyboard.DOWN) {
downPressed = false;
}
if (e.keyCode == Keyboard.LEFT) {
leftPressed = false;
}
if (e.keyCode == Keyboard.RIGHT) {
rightPressed = false;
}
if (e.keyCode == Keyboard.W) {
WPressed = false;
}
if (e.keyCode == Keyboard.S) {
SPressed = false;
}
if (e.keyCode == Keyboard.A) {
APressed = false;
}
if (e.keyCode == Keyboard.D) {
DPressed = false;
}
if (e.keyCode == Keyboard.ENTER) {
enterPressed = false;
}
if (e.keyCode == Keyboard.SPACE) {
spacePressed = false;
}
}
function deg2rad(deg: Number): Number {
return deg * (Math.PI / 180);
}

function playGame(e: Event): void {
var i: int;
var dx: Number;
var dy: Number;

if (upPressed) {
car2.moveForward();
}
if (downPressed) {
car2.moveBackward();
}
if (leftPressed) {
car2.turnLeft();
}
if (rightPressed) {
car2.turnRight();
}
if (WPressed) {
car1.moveForward();
}
if (SPressed) {
car1.moveBackward();
}
if (APressed) {
car1.turnLeft();
}
if (DPressed) {
car1.turnRight();
}
if (dot1Ready) {
dot1.x = car1.x
}
if (dot2Ready) {
dot2.x = car2.x
}
if (carshield2 == 0) {
trace("Game Over");
gameOver.text = String("Blue Car win");
}
if (carshield1 == 0) {
trace("Game Over");
gameOver.text = String("Red Car win");
}
if (!spacePressed && dot1Ready) {
trace("dot1 ready");
dot1.y = car1.y;
dot1.x = car1.x;
dot1.rotation = car1.rotation;
addChild(dot1);
dot1Array.push(dot1);
dot1Ready = false;
}
for (i = 0; i < dot1Array.length; i++) { // move dots in array
trace("move dot1");
if (dot1Array[i].y < 0) {
removeChild(dot1Array[i]); // remove when goes out of stage
dot1Array.splice(i, 1);
} else {
dy = Math.sin(deg2rad(dot1Array[i].rotation)) * dotspeed;
dx = Math.cos(deg2rad(dot1Array[i].rotation)) * dotspeed;
dot1Array[i].y = dot1Array[i].y + dy;
dot1Array[i].x = dot1Array[i].x + dx;
if (car2.hitTestObject(dot1Array[i])) {
carshield2 = carshield2 - damage;
carmeter2.height = carshield2;
removeChild(dot1Array[i]);
dot1Array.splice(i, 1);
} else if (carshield2 == 0) {
trace("Game Over 2");
gameOver.text = String("Blue Car win");
}
}

}

if (!enterPressed && dot2Ready) { // launch a dot by adding to array
trace("dot2 ready");
dot2.x = car2.x;
dot2.y = car2.y;
dot2.rotation = car2.rotation;
addChild(dot2);
dot2Array.push(dot2);
dot2Ready = false;
}

for (i = 0; i < dot2Array.length; i++) { // move dots in array
trace("move dot2");
if (dot2Array[i].y < 0) {
removeChild(dot2Array[i]); // remove when goes out of stage
dot2Array.splice(i, 1);
} else {
dy = Math.sin(deg2rad(dot2Array[i].rotation)) * dotspeed;
dx = Math.cos(deg2rad(dot2Array[i].rotation)) * dotspeed;
dot2Array[i].y = dot2Array[i].y + dy;
dot2Array[i].x = dot2Array[i].x + dx;
if (car1.hitTestObject(dot2Array[i])) {
carshield1 = carshield1 - damage;
carmeter1.height = carshield1;
removeChild(dot2Array[i]);
dot2Array.splice(i, 1);
} else if (carshield1 == 0) {
trace("Game Over");
gameOver.text = String("Red Car win");
}

}

}
}

every time i click the button that error appears