Form List/Menu with with secondary options to select

Hi I am newbie here. I've created a form in DreamWeaver and need two things.

1 - I need to know how to use CGI to submit the form
2 - I can't figure out how to make a list/menu that, when user rolls over or selects an item in the list a secondary options pops out to be selected and submitted with data.

Example:

Turkey Sandwich:
mustard
mayo
pickle

Any help is appreciated. Thanks

JP