Trigger rails 3 form submit without using the submit button

ajax_forms.html

<script type="text/javascript">
  function send(){
    // check "send_now" and submit using ajax
    // Assumes you're using jquery.rails.js
    $("#send_now").val("true");
    $("#f").trigger("submit");
  }; 
</script>

<input type='hidden' id='send_now' name='send_now' />

<button type="button" onclick="send();" class='btn gray_btn'><%= t('action.send') %></button>

DONT'T FORGET the hidden field - it must have a name and the id must match the reference in the javascript.
Also, make sure the form ID is f (or whatever you reference in the javascript)