Form submitted twice in Chrome/Safari

Question

I am seeking to perform a basic form post, but the following submits to the server twice in Chrome and Safari (but behaves as expected in Firefox):

<form id="create-deck-form" action="/decks/create" method="post">
  <fieldset>
    <legend>Create new deck</legend>
    <label for="deck-name-field">Name</label>
    <input id="deck-name-field" name="deck-name-field" type="text" value="" maxlength="140" />

    <label for="tag-field">Tags</label>
    <input id="tag-field" name="tag-field" type="text" value="" maxlength="140" />

    <input class="add-button" type="submit" value="Create" />
  </fieldset>
</form>

I would like to use the onsubmit attribute to perform validation on the fields before submission, but wherever the return value is true, the form is submitted twice.

I have sought to bind a jQuery handler to the form, but here too, where the default behaviour is not prevented, the form is submitted twice, e.g.:

<script type="text/javascript">
 $(document).ready(function() {
     $("#create-deck-form").submit(function(event){
          if($("#deck-name-field").val() == "") {
            event.preventDefault();
            alert("deck name required");
          }
        });
 });
</script>

While I suppose there is something blindingly obvious wrong here to a fresh pair of eyes, I am deeply confused why submission, with or without validation, makes a duplicate post to the server in Chrome and Safari. I'd be grateful for any insight.

Answer 1

This issue is actually associated with Facebox (http://defunkt.github.com/facebox/). Facebox initialization causes a second set of requests after your page loads. So, if you post to /myaction/create, Facebox will start a second set of requests with the base URL set to /myaction/create. A fix is to redirect to a URL which handles get requests after doing a post, so you don't end up performing the post twice. Thanks very much for your help.