Submitting a form via AJAX not working

I am trying to use Jquery and AJAX to submit a small contact form without page refresh. I got the code from another Stackoverflow thread but when I try to submit a form and click submit button nothing happens. I don't even get any error messages on console also . So can any one tell me what I am doing wrong here. Here is the form

 <form id="contactform" name="contactForm"> <input type="text" name="name"/><br/> <input type="text" name="email"/><br/> <textarea name="comment"> </textarea> <p style='text-align:right;'><input type="submit"/></p> </form> 

Here is JS:

<script> // variable to hold request var request; // bind to the submit event of our form $("#contactform").submit(function(event){ // abort any pending request if (request) { request.abort(); } // setup some local variables var $form = $(this); // let's select and cache all the fields var $inputs = $form.find("input, select, button, textarea"); // serialize the data in the form var serializedData = $form.serialize(); // let's disable the inputs for the duration of the ajax request $inputs.prop("disabled", true); // fire off the request to /form.php request = $.ajax({ url: "form.php", type: "post", data: serializedData }); // callback handler that will be called on success request.done(function (response, textStatus, jqXHR){ // log a message to the console console.log("Hooray, it worked!"); }); // callback handler that will be called on failure request.fail(function (jqXHR, textStatus, errorThrown){ // log the error to the console console.error( "The following error occured: "+ textStatus, errorThrown ); }); // callback handler that will be called regardless // if the request failed or succeeded request.always(function () { // reenable the inputs $inputs.prop("disabled", false); }); // prevent default posting of form event.preventDefault(); }); </script> 

and finally here is post.php file.

<?php echo $_POST['fullname']."<br/>"; echo $_POST['email']."<br/>"; echo $_POST['comment']."<br/>"; ?> 

Here is the url of the page which has the form: http://contestlancer.com/davidicus/

If you click on the small message icon in the header logo you will see contact form.

Regards Ahmar