Please help I'm stuck on sub menus

I am designing a web page and I am stuck on how to create sub menus

I have already created a basic menu but now I want a menu that pops out the sub menus when the mouse is over it.

for example

Sport is the main menu and I want the sub menus Football and Golf to appear one after the other in a list once the mouse is moved over them.

e.g.

SPORT
Football
Golf

What would be the code (HTML code) befor the above plan, using Dreamweaver MX 2004? Or would I have to use javascript?

Thanks for your help