Creating an Alert Box with Swing/mxj

OK, I was worried that calls to outlet would cause more threading
problems,
as they run in in a Max thread. But from the 'Writing Max externals
in Java'
document from Topher I understand that this is safe to do (v0.3 page 42)
"It is worth noting that when using Java threads inside of your Max
external, any outlet
calls you make back into the Max application will automatically be
deferred for handling
by the low-priority main thread for normal outlet calls and the high-
priority scheduler
thread for outletHigh calls."

One thing puzzles me: why is there no hang up on WinXP?
Anyway, I am glad to have learned about invokeLater().

For the sake of archiving, I'll post my edition of your code below.
-jennek

//
//    SaveChanges.java
//
//    01.21.06, Henry Till (henrytill@gmail.com)
//

import com.cycling74.max.*;
import javax.swing.*;

public class SaveChanges extends MaxObject {
    String name = null;

    public SaveChanges(Atom[] atoms) {
        declareInlets(new int[] { 1 });
        declareOutlets(new int[] { 1 });
    }

    public void bang() {

        SwingUtilities.invokeLater(new Runnable() {
            public void run() {

                Object[] options = { "Don't Save", "Cancel", "Save" };

                int n = JOptionPane
                        .showOptionDialog(null, // null to hatch from parent
                                                // frame
                                "Do you want to save changes to " + name,
                                "Save Changes?",
                                JOptionPane.YES_NO_CANCEL_OPTION,
                                JOptionPane.QUESTION_MESSAGE, null, options,
                                options[2]);

                if (n == JOptionPane.YES_OPTION) {
                    outlet(0, "2");

                } else if (n == JOptionPane.NO_OPTION) {
                    outlet(0, "0");
                } else if (n == JOptionPane.CANCEL_OPTION) {
                    outlet(0, "1");
                } else {
                    post("no answer given");
                }

            }
        });

    }

    public void inlet(int i) {
    }

    public void inlet(float f) {
    }

    public void list(Atom[] list) {
    }

    public void anything(String s, Atom[] args) {
        if (s.equals("name"))
            name = Atom.toOneString(args);
    }

}