I know how to do it with a hover popup using just CSS and no javascript; see the general principles for a simple menu here:-
http://www.wickham43.supanet.com/tut...verpopups.html
the popup can be positioned where you want by editing the left and top positions so that each menu button has a popup in the same place.
You have to use javascript to hold the popup after clicking but remember that once you have clicked the link you will open the new page unless the link has no page to go to.
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.