Newbie question: Transferring values to a text field

Hi.

I have a simple question. Looks like it's something basic.

I have 2 elements: a form with a textfield and a link (father), and a
panel with a link that includes a value inside (child). Here's how my
analogy works:

- First you click on the link of the "father" to make the "child"
appear (with an "Effect.Appear" command).
- Then you click on the link, and two processes are done here:

The value is passed to the textfield.
The "child" dissapears (with an "Effect.Fade" command)

To tell you the truth, I have made and example code of the view
(without the value transfer to the textfield):

#index.html.erb:
<% form_tag :action => 'access' do %>
<p><label for="user_username">Username</label>:
<%= text_field 'user', 'username' %></p>
<p><label for="user_passwordkey">Password</label>:
<%= text_field 'user', 'passwordkey' %></p>
<%= submit_tag "Enter" %>
<% end %>
<p id="search_link"><%= link_to_function("User missing?",
"Effect.Appear('search'); return false;") %></p>
<div id="search" style="display:none;">
<p>User search:</p>
<p><%= link_to_function("My User",
"Effect.Fade('search'); return false;") %></p>
</div>

Can you tell me what's missing or wrong? I would like to know, because
I'm beginning with Rails 2.1. I know it can be done on standard HTML
and Javascript. So I want to do it on Rails.

BTW, I'm using scrpit.aculo.us for this example to make it feel alive!

Greetings...

The Neurochild.