public String changePassword(String prompt) 
{
        Window w = (parent == null) ? null
                                    : (Window) SwingUtilities.getAncestorOfClass(Window.class,
                parent);
        PasswordChangeDialog dialog = null;
        if (w instanceof Frame) {
            dialog = new PasswordChangeDialog((Frame) w, prompt);
        } else if (w instanceof Dialog) {
            dialog = new PasswordChangeDialog((Dialog) w, prompt);
        } else {
            dialog = new PasswordChangeDialog(prompt);
        }
        char[] p = dialog.getPassword();
        return (p == null) ? null : new String(p);
}

 public static PasswordChange getInstance() 
{
        if (instance == null) {
            instance = new PasswordChange();
        }
        return instance;
}

 public  void setParentComponent(Component parent) 
{
        this.parent = parent;
}