Using the code listed below, showInternalConfirmDialog always return
the value -1 and disappears as soon as its dialog comes up.
Running on JDK-1.2-V, this code works properly as expected.

import java.awt.*;
import javax.swing.*;

public class Test extends JFrame {

    public Test() {
        super("Test");
    }

    public static void main(String args[]) {
        Test test = new Test();
        test.run(args, System.err, System.out);
    }

    public void run(String args[], java.io.PrintStream log, java.io.PrintStream out) {
        JDesktopPane dp = new JDesktopPane();
        JOptionPane op = new JOptionPane();
        JInternalFrame iframe = op.createInternalFrame(dp, "iframe");
        int result = 0;

        setBounds(100, 100, 300, 300);
        setVisible(true);
        result = op.showInternalConfirmDialog(getContentPane(), "test");
        out.println("result: " + Integer.toString(result));
        quit();
    }

    void quit() {
        dispose();
        System.exit(0);
    }
}

kenichi.kurosaki@Japan 1999-07-23