If you're looking to do a dropdown menu I can help with the code for that (presuming you mean an option box..)
Option 1 of drop down menu Option 2 of drop down menu
Remove all of the - in it. I can't show you the code in here without the dashes otherwise it creates a dropdown menu for me!
Here is a tutorial I found by quickly searching on Google with an explanation behind the select box; link text
If you're looking for a drop down menu for navigation Dynamic Drive have all sorts of navigations, both in HTML and in CSS, take a look around their site, they have a lot of useful examples!