change parameters to periodically_call_remote

Hi,

I have a search box (id=:phrase) on my rails ajax page. I want a
periodically call remote poller to update a div whenever the value in
that box changes.

On the page containing the search box, I have the following:
<%= periodically_call_remote(:url => update_query_topics_url,
  :with => "$('phrase').serialize()",
  :frequency => 1.0)%>

I have also tried:

<%= observe_field(:phrase, :url => update_query_topics_url,
  :with => "$('phrase').serialize()",
  :frequency => 1.0)%>

The issue is that the phrase value is not picked up when it changes in
either case. The update continues to use the first phrase value,
unless the page is refreshed.

I also tried assigning the phrase from the rjs on clicking the submit
button beside the search box:

page.assign "phrase", @query.phrase

However, the only way to get the periodically_call_remote or the
observe_field seems to be to refresh the page.

How do I get the update to happen whenever the phrase changes? I need
the poller, because the actual retrieving of topics based on the query
will run in a delayed job.

Thanks
Anand