title: Changing from observe_field to JQuery in Rails 3
body: <p>Prior to Rails 3, I used this code to observe a field dynamically and pass the data in that field to a controller:</p>
  
  <pre><code>    &lt;%= observe_field :transaction_borrower_netid,
      :url =&gt; { :controller =&gt; :live_validations, :action =&gt; :validate_borrower_netid },
      :frequency =&gt; 0.5,
      :update =&gt; :borrower_netid_message,
      :with =&gt; "borrower_netid" %&gt;
  </code></pre>
  
  <p>I'm trying to update that code to work with Jquery and Rails 3, but I can't get it to work.  I updated my <strong>routes.rb</strong> to include</p>
  
  <pre><code>  match "/live_validations/validate_borrower_netid" =&gt; "live_validations#validate_borrower_netid", :as =&gt; "validate_borrower"
  </code></pre>
  
  <p>and I'm trying to observe the field and make the necessary calls with:</p>
  
  <pre><code>    jQuery(function($) {
    // when the #transaction_borrower_netid field changes
    $("#transaction_borrower_netid").change(function() {
      // make a POST call and update the borrower_netid_message with borrower_netid
      $.post(&lt;%= validate_borrower_path %&gt;, this.value, function(html) {
          $("#borrower_netid_message").html(html);
      });
    });
  })
  </code></pre>
  
  <p>but it's not working.  My Javascript and Jquery skills are severely lacking, so any help anyone could provide would be much appreciated.  Thanks!</p>