Creating dynamically expanding forms


I'm learning Rails right now, and as my first project I am trying to
create a fun little useful website. However, I'm getting stuck on one
of the steps, and was wondering what the easiest approach would be.
What I'm specifically looking to do is to create "dynamic" forms,
where the number of fields can be increased and decreased by the user.
I'm referring to something like the functionality of phpMyAdmin, where
the user has the option to keep adding columns to a table. It would be
something like this: the form starts out with fields to input a street
address. Then, when the user is finished adding that address, he has
the option "Enter another address", and if he clicks on that button, a
new set of fields is created, and which the a user can fill out the
new address, until he feels he is finished. This is the same concept
used on the following site for entering email addresses:

What would be the easiest way to do this? I figure it can be done
server-side or client side; what's the best way?



Sorry, I realized the link I entered goes to the wrong page. Please
ignore it.

But does anybody know the best way to create dynamically expanding

Maybe will help?


Thanks! I'll have a look at it.