Hi Johny,
Daniel likes this group to concentrate on issues with BlueGriffon itself
rather than dealing with HTML and CSS coding techniques. The trysnowball
site uses some quite sophisticated CSS techniques to achieve what you
want (and all its other visual gimics) and you'll need to be reasonably
competent in CSS to adapt them.
Have you tried a search for "css popup box" and looked at the techniques
some of those results give you? If you need something aimed more at the
beginner then, although branded as a site concentrating on KompoZer, you
may find the forum at:
http://wysifauthoring.informe.com/forum/
is a better place for help with coding in a BlueGriffon environment.
--
Greg Chapman
http://www.gregtutor.co.uk
Still helping users of KompoZer but using BlueGriffon