Using jQuery .post function in a wordpress custom template form

[admin]

I'm currently whipping up a custom contact form on a wordpress site which I'm trying to submit via ajax with jQuery, however when I perform the $.post function, firebug is reporting a 404 error in the console even though I can type the URL in to my address bar and display the page correctly. I am not posting cross-domain.

Here is an example of my code, with irrelevant code removed:

<form action="" method="post" onsubmit="return submitContactForm()" class="contactform">
 <!-- inputs etc here -->
</form>

<script type="text/javascript">
function submitContactForm() {
  // Omitted error checking here, return false on error
  $.post('/contact'/, $('.contactform').serialize(), function(data) {
    alert(data);
    return false;
  });
  return true;
}
</script>

The post is never successful and the form submits the "normal" way every time.

I've tried many combinations in the url part of $.post including /contact/ , /contact , contact , /contact/, even the full url of the site with no luck. Has anybody had this issue before? Or am I doing something blatantly wrong? My only guess is something to do with my /%postname%/ permalink structure, other than that I'm clueless!

Any ideas/thoughts appreciated

Thanks, Andy