conditional form element

I have a button option in my form with 2 options. User may only select
one of the options. Based on the option they choose I want an
associated select list to appear. I'm guessing this can only be done
with javascript or can it be done with just Ruby ?

TIA
Stuart

In case this wasn't clear I wanted to elaborate a little more.
The user would choose from either an "annual" or "hourly" option.
Based on that there would be a list listing dollar amounts. When I
first built the amounts table there was a secondary id column , where
id-1 was annual and id-2 was hourly.
Anyway, I guess this is a javascript thing but then would the whole
template need to be a rjs ?
Also if there are any pure Ruby options to accomplish this , that
would be better.

TIA
Stuart

Why not use Ajax? You could use form_remote_tag to make the annual and
hourly buttons into forms (independent of your main form) (iirc you
can't nest forms).

You could then wrap the dollar-amount-selector (and a hidden
annual-or-hourly text field, if needed) in a div and have the contents
of that div replaced by the server whenever the annual or hourly
buttons were clicked.

(Yes it is all javascript behind the scenes, but javascript which has
already been written.)

Hope it helps,

Regards

Chris.

Why not use Ajax? You could use form_remote_tag to make the annual and
hourly buttons into forms (independent of your main form) (iirc you
can't nest forms).

I don't believe there is a reason couldn't nest forms.

You could then wrap the dollar-amount-selector (and a hidden
annual-or-hourly text field, if needed) in a div and have the contents
of that div replaced by the server whenever the annual or hourly
buttons were clicked.

This would still show up within the main form ? And do I move
everything to a RJS template ?

Stuart