Although I am new to Dreamweaver and I cannot call myself an expert try going to the Insert menu > Spry and choose whatever Spry Effect you want: Accordion, Menu, Collapsible Panels, Tabbed Panels, etc.
Hope this can help you
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.