window = new JWindow();
window = new JWindow(SwingUtilities.getWindowAncestor(owner));
    public JWindowPopup(Component owner, Component contents,                        int x, int y)    {      /* Checks whether contents is null. */      super(owner, contents, x, y);      this.contents = contents;      window = new JWindow();      window.getContentPane().add(contents);      window.setLocation(x, y);      window.setFocusableWindowState(false);    }