The menu bar is the menu for the popup window. By default popups don't have menu bars. You can configure the popup to have a menu by setting
yes in the
open() command. So, for example, this
open() command in the
configures the popup to have a menu bar:
window.open(href, windowname, 'width=400,height=150,menubar=yes,scrollbars=yes');
which gives us this popup.