thank you very much ...  I cannot believe how complicated it is to open
a new window from an applet (not new App, new window..) this is simply
for a chat app applet, chat window opens in a new window (new window
doesn't mean a separate app.. just means user opens chat app, logs in,
chat window opens..)  I think I may not have made myself clear..

I already wrote my chatApp interface, now have to change a whole lot to
open from applet main window (you know, like a splash window..)   :(

inner classes...
EDT..
ok, need to figure all this out...  (so what is now in init() method in
my chat window interface now goes in an inner class?)

regarding EDT.. from pg previously mentioned..

"Swing components should be created, queried, and manipulated on the
event-dispatching thread, but browsers don't invoke applet "milestone"
methods from that thread. For this reason, the milestone methods — init,
start, stop, and destroy — should use the SwingUtilities method
invokeAndWait (or, if appropriate, invokeLater)"

now these invokeAndWait and invokeLater -- are THESE the event-handling
threads?
(I was not able to compile code you posted (MyApp.java and frame.java..)

I do understand basic concept of threads (to run several processes at
the same time, let's say several connections from a client to a server,
or several simultaneous connections to a db...) but I don't understand
why you need to do this to display Swing GUI elements..

again, thank you very much for your time..

take that back..  WAS able to compile code you posted (hadn't imported
necessary classes..) only one of them, though, on frame.java, get these
two errors:

frame.java:7: 'class' or 'interface' expected
private JFrame frame;
        ^
frame.java:10: 'class' or 'interface' expected
public void init() {
       ^
2 errors

first line here is

    private JFrame frame;

this looks like a var init..  don't see a class declaration here..  this
is not a separate class?  (the frame to be opened?)

MyApp compiles fine but when try to run ("java MyApp") get this error..
Exception in thread "main" java.lang.NoClassDefFoundError: MyApp/java

again, many thanks..  Frances

thank you very much the Thomases, the Andrews, Roedy, for your help.. I
finally got my window to open from a JApplet..

        window OPENED:
 public class ChatRoom extends JFrame implements ActionListener,
KeyListener {
 //  decl vars...
           ChatRoom(String title) {
         super(title);
             init();
 }

     code that opens this window:
public class oWin extends JApplet implements ActionListener {
       JFrame window;
        .....
    public void init() {
          ....
window = new ChatRoom("The Chat Window -- from opener");
}

public void actionPerformed(ActionEvent ae) {
        if (!window.isVisible()) {
      window.setVisible(true);
    }
          return;
    }
       
does this sound about right?  reason I'm asking is that Thomas Hawtin
said, "you don't even need to extend JFrame except in specialist cases.."

so I changed this..
    public class ChatRoom extends JFrame implements ActionListener,
KeyListener {

to this..

 public class ChatRoom implements ActionListener, KeyListener {
 JFrame window = new JFrame();
      but get errors (

(even though window opens fine now I need to make sure this works right
when it runs "for real" -- connecting to server, sending messages, etc..)

Thomas also says to open window from event-dispatch thread..  but I have
action to open window inside ActionPerformed() method..  where do I put
invokeListener() method (this is event-handling method?)

I'm trying to follow a simple model from this page,
http://java.sun.com/docs/books/tutorial/uiswing/learn/example1.html)

here invokeLater() is inside main method..  but Thomas Hawtin in same
post mentioned above said that a swing window that is not a JApplet
doesn't need an init() method NOR a main method..  (so, put
ActionPerformed() inside main method?  help pls, am confused...  threads
my main problem right now...)  ok, lots of questions, I know..  thank
you very much...