Really Basic OO Class Question...

Question

heres the complete code for my applet...As i understand it this should make a "Car" class then should be generating a "car" object with the constructors marked...then i just use the g.drawstring to output this...but i get a nasty error message. Its something really simple, but its completely vexed me...thanks in advance.
import java.applet.*;
import java.awt.*;
public class Traffclass extends Applet {
     public void init() {
     public class Car {
          public int length, width;
          public Color carColor;
          public Car() {  //constructor?
               length = 7;
               width = 5;
               carColor = new Color(200,10,60);
     private Car car = null;
     public void run() {
          car = new Car();
          repaint();
     public class Trafficlight {
          public boolean greenlight = true;
     public void paint(Graphics g) {
          g.drawString(""+car.length, 50, 60 );
     //     g.fillRect(car);
}

Answer 1

As stated the problem is solved now, but heres the error message in question...
Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException
        at Traffclass.paint(Traffclass.java:39)
        at sun.awt.RepaintArea.paintComponent(RepaintArea.java:248)
        at sun.awt.RepaintArea.paint(RepaintArea.java:224)
        at sun.awt.windows.WComponentPeer.handleEvent(WComponentPeer.java:254)
        at java.awt.Component.dispatchEventImpl(Component.java:4031)
        at java.awt.Container.dispatchEventImpl(Container.java:2024)
        at java.awt.Component.dispatchEvent(Component.java:3803)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
grantedIt wasn't a compiler message (what i am used to) so it threw me a bit.