Thread in infinite loop, won't allow anything else to happen...help appreci

Question

Basically, i'm trying to make a basic traffic simulator, and learn java at the same time, so bare with me...
I want a couple of threads to run concurrently in the applet, but am having touble. Basically one starts inside the run() and works fine, but the other wont...infact nothing after the first thread will run (i.e. if the repaint() goes after the end of catch{}). The source is a bit of a mess with no comments, but its all really basic so should be easy for even the elementary java programmer to understand.
I know the second thread (well what i hope is a second thread) doesn't actually do anything other than output a line that could be done by the first thread, but its just proof of concept for now, i will put stuff in there later.
source, class and html are here:
http://www.soton.ac.uk/~tr403/traff/
also the slider in the bottom right doesn't appear in the browser unless you click on it, but in the applet viewer it comes up...why is this? its at the bottom of my priorities at the mo, but its puzzling, and obviously something really elementary.
Any help MUCH appreciated, its for my dissertation which has got be to handed in on may 11th ;)
This the run bit, initated from the start [method? not sure on terminology yet]
public void run()
              Thread carmove = Thread.currentThread();
               try {
               while (carmove != null){
               Thread.currentThread().sleep(carsptimeout);
               xcount++;
               repaint(0,144,300,5);
               if (xcount == maxlength1){
                    xcount = 0;
            catch (InterruptedException e){}
                 Thread sysline = Thread.currentThread();
               try {
                    while (sysline != null){
                    Thread.currentThread().sleep(carsptimeout);
                    System.out.println(xcount);
               catch (InterruptedException e){}
     public void stateChanged(ChangeEvent e)
          tempreadout.setText
               (" " + (slider.getValue()));
          carsptimeout = 100 - (int)slider.getValue();
         public void update(Graphics g)
              paint(g);
        }

Answer 1

This sounds like something i can do...not sure how
its gonna effect the slider at the bottom but will do
it anyway.Think of your applet as a bunch of cards on top of each other.
+----------------------+
| APPLET               |
|                      |
|                      |
|  --------          |
|  | button |          |
|  --------          |
----------------------Each card call the paint on all its childern. You override the paint, so it it does not call "paint" on its childern. By moving the draw into a different JPanel, which has no childern, the fact that you don't ask for its childer to be drawn does not matter.
| Applet               |
| -----------------  |
| |DrawTraficlights |  |
| -----------------  |
|                      |
|  --------          |
|  | button |          |
|  --------          |
Any ideas on my threads?Redesign.
Create a class for object type in your world. Only "extend" a different class if that makes sence.
What is a "sysline"?
Why is trafic light moving cars forward?