Rails Trying to submit a form onchange of dropdown

Question

I have my Ajax working, builtin Rails javascript, with the submit button. However, I would like it to submit when I change the value of the dropdown box and eliminate the button. In my research I found what looks like the correct solution but I get no request to the server. Here is my dropdown form code, note it still has the submit button that worked before I added :onchange:

<% form_tag('switch_car', :method => :put, :remote => true) do %>
  <div class="field">
    <label>Car Name:</label>
    <%= select_tag(:id, options_from_collection_for_select(active_cars, "id", "name"), 
       :onchange => ("$('switch_car').submit()"))%><%= submit_tag "Switch Car" %>
  </div>    
<% end %>

Here is the HTML generated:

<form accept-charset="UTF-8" action="switch_car" data-remote="true" method="post">
  <div style="margin:0;padding:0;display:inline">
    <input name="utf8" type="hidden" value="&#x2713;" />
    <input name="_method" type="hidden" value="put" />
    <input name="authenticity_token" type="hidden" value="PEbdqAoiik37lcoP4+v+dakpYxdpMkSm7Ub8eZpdF9I=" />
  </div>
  <div class="field"> 
    <label>Car Name:</label> 
    <select id="id" name="id" onchange="$('switch_car').submit()">
      <option value="9">Truck</option>
      <option value="10">Car</option>
    </select>
    <input name="commit" type="submit" value="Switch Car" /> 
</div> 

Thanks in advance for any help.

Answer 1

Depending on the js library you are using:

Prototype: :onchange => ("$('switch_car').submit()")

Jquery: :onchange => ("$('#switch_car').submit()")

If you are using the defaults and your rails version is below 3.1, then prototype is the default library.