Google "Mouseover javascript".
One link is:-
http://www.hypergurl.com/rolloverimage.html - make sure javascript is enabled.
You need two images for the buttons.
If you are using just different colors for the buttons there are pure CSS codes which don't need javascript:-
http://www.wickham43.supanet.com/tut...downmenus.html
you use just part of the dropdown menu code without the dropdown, like the Advice button.
You can use pure CSS with two images:-
http://www.wickham43.supanet.com/tut...verpopups.html
the popups would be the same size as the original positioned in the same place;
but it is a bit fiddly to set up and perhaps javascript is easier.
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.