Hi,

Have you looked at the API documentation?
http://java.sun.com/j2se/1.4.2/docs/api/javax/swing/PopupFactory.html

Like it says on there...

PopupFactory factory = PopupFactory.getSharedInstance();
Popup popup = factory.getPopup(owner, contents, x, y);
popup.show();
...
popup.hide();

You usually don't create an instance of Popup, rather you use the
Popupfactory's method getPopup() to obtain one.

Then use the show() method to make it visible, and once you are done
with whatever you have to do, call the hide() method to close and
dispose of the Popup

-Mike