problem with the pong game

[bibi822]

How can I add edit so that when the number of lives reaches 0, it will go to frame 6 for a "Game Over" screen. I thought it's


if(numberOfLives<=0) //if the user runs out of lives
{
gotoAndStop('gameover'); //go to gameover frame
}

This is the whole code

var howFarToMoveTheX:Number = 18; //this sets the x speed
var howFarToMoveTheY:Number = 18; //this sets the y speed
var numberOfLives:Number = 3;

lives.text = String(numberOfLives);


//ball function begins here

circle_ball.addEventListener(Event.ENTER_FRAME, moveBall);

function moveBall(event:Event):void
{
circle_ball.x += howFarToMoveTheX;

if (circle_ball.x >= 535) //sets the ball to the right at 550 on the x coordinates

{
howFarToMoveTheX = -howFarToMoveTheX; //you can write -7 or -howFarToMove
//trace(34343);
}

if (circle_ball.x <= 0)
{
howFarToMoveTheX = -howFarToMoveTheX;
}

// the y coordinates begin here which makes the ball move vertically
circle_ball.y += howFarToMoveTheY;
if (circle_ball.y >= 400)
{
//howFarToMoveTheY = -howFarToMoveTheY;
//LOSE A LIFE, and reset ball position
circle_ball.x = 274.50;
circle_ball.y = 164.55;
numberOfLives--;
lives.text = String(numberOfLives);
}
if (circle_ball.y <= 0)
{
howFarToMoveTheY = -howFarToMoveTheY;
}

if (circle_ball.hitTestObject(paddle_square)) //ball and paddle interaction
{
howFarToMoveTheY = -howFarToMoveTheY;
}

if(numberOfLives<=0) //if the user runs out of lives
{
gotoAndStop('gameover'); //go to gameover frame
}

}

//paddle function begins here
stage.addEventListener(MouseEvent.MOUSE_MOVE, movePaddle);

function movePaddle(event:MouseEvent):void
{
paddle_square.x = mouseX; //move the mouse on the x coordinates
Mouse.hide(); //hide the mouse arrow
}