java confirmation dialog

we've got a confirmation dialog applied when closing a
window...there's the usual yes and no option in the dialog...when
pressing the yes window the window closes it also happens when you
press the no button which is not suppose to happen...instead the
confirmation dialog closes but the window is still there...

Code:

this is the codes we've got...

this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e)
{
if(JOptionPane.showConfirmDialog(container,
"Are you sure you want to leave the conference ?",
"iMessage: Quit Conference",
JOptionPane.YES_NO_OPTION,
JOptionPane.QUESTION_MESSAGE,
null) == JOptionPane.YES_OPTION) {
Message mymessage = new Message(CONFERENCE_LEAVE);
mymessage._destination = user.toString();
try {
frame.sendMessageToServer(mymessage);
}
catch(Exception se) {
System.out.println("Error sending message");
}
//setVisible(false);
//frame.removeFrame(user);
}


In this code as i see , the only thing will lead the man window to
close(not visiable only) is the commented lines of code :

//setVisible(false);
and u made a condition if for YES option and with no else ... so i
think setVisible false called in both before you comment it .
don't use setVisiable function to close window , use :
dispose()