check_box and rjs

Hi,
In my view I currently have the following link which show/hides a div
      <%= link_to_function "Show Hide" do |page|
        page[:user_input_name].toggle
      end %>

Instead of using a link to do the show/hiding I would like to use the
onclick event of a checkbox. I understand that I can add javascript to
the onclick event as follows:
   <%= form.check_box :io_1 ,{:onclick => "alert('Testing');"}%>

However, is it possible to use rjs code in the onclick part of the
form.check_box?
I know that i can look at the view and grab the javascript generated by
the link and explicitly paste that into the onclick part but I like
using the RJS syntax. Is it possible? e.g. something like:
   <%= form.check_box :io_1 ,{:onclick => do |page|
page[:user_input_name].toggle end }%>

Thanks

That's basically what update_page does. The name is a bit misleading, but basically it yields the same thing as you get in a render :update or the magic page object in a rjs file and returns the generated javascript.

Fred

sorry, so how do I use updaet_page in conjuction with a checkbox? The
following doesn't work:
<%= form.check_box :io_1 , update_page{|page|
page[:user_input_name].toggle}%>

Apologies, I was being stupid. The correct way is:
      <%= form.check_box :io_1 , :onclick => update_page{|page|
page[:user_input_name].toggle}%>

Thanks for your help