How To Create Drop Down Definitions

["GeekyGirl406" <webforumsuser@xxxxxxxxxxxxxx>]

I want my visitors to be able to click on a word and have the definition appear 
either in a little box or or next to the word. 

 I notice in Dreamweaver CS3 on the Text tab, there are three buttons 
associated to definitions (dl, dt, dd).  I can't find anything in the help 
about these buttons.  Are these the buttons I need to use to do what I want? If 
so, how do I use them.  if not, how do I set up the page to allow for these 
definitions to be part of my page?

 Any direction would be great!