Ruby Forum Test > :update to list

I have this list and what I want to do is to have a link that allows the
user to add something to this list. So I have a form with the :update
option, but I want the update to happen at the end of this div that I
have set aside for this list. I don't remember how to use :update and
tell it to add at the end of the list. Or is it done with render? Can
anyone help, Thanks,

-S