I need help with Applets and Multithreading

Question

[hello all.  first time poster. big fan of java.]
now to the important matter: Applets and Threads
=======================================
1) I have an applet with that implements the runnable interface, and has one thread (and a simple animation). If I try to view this applet in the applet viewer with JGrasp, it spits an insane error telling me
"java.security.AccessControlException: access denied (java.lang.RuntimePermission modifyThreadGroup)"
but, if I run the applet through a web browser, by putting it in an html document, it runs correctly, without error
What on earth is wrong, and how do I fix it?!?
2) I want to put 2 threads in my applet?
If I implement the Runnable interface, I can only have one Run() method in my applet, right?
So how do I define behaviour for 2 threads when I only have one run method in which to define the behaviour? Can I use two threads with the runnable interface, or do I have to make objects of my own defined thread classes?
3) I tried to make 2 threads in my applet by creating my own thread classes, and instantiating them in my applet (instead of implementing the runnable interface).
I still get the same insane error as I mentioned in my first point (which I expected), except now, the applet won't work even when viewed through a web browser!!
Please please help me. I am frustrated beyond belief (at what is probably a very simple problem)
I have searched and searched all over and found no answers on this

Answer 1

If I try to view this applet in the applet viewer with JGrasp, it spits an insane error telling me
"java.security.AccessControlException: access denied (java.lang.RuntimePermission modifyThreadGroup)"Don't know anything about JGrasp, but it runs with pretty tight security - thats what this insane error is all about. Use the appletviewer or a browser.
If I implement the Runnable interface, I can only have one Run() method in my applet, right?Correct
So how do I define behaviour for 2 threads when I only have one run method in which to define the behaviour?
Can I use two threads with the runnable interface, or do I have to make objects of my own defined thread classes?You can create two Runnable implementations (classes) in your applet.
example (missing code)
class MyApplet extends Applet {
  void doSomething() {
  void doSomethingElse() {
  void startThreads() {
    Thread t = new Thread(new Runnable() { public void run() { doSomething();}});
    t.start();
    t = new Thread(new Runnable2());
    t.start();
  class Runnable2 implements Runnable {
     public void run() {
       doSomethingElse();
}If the above seems confusing, read up on anonymous and inner classes.
3) I tried to make 2 threads in my applet by creating my own thread classesTry not subclassing thread - this causes a security check