Javascript Submit button not sending anything

Code

//Signup Form.

        (function() {



            // Vars.

                var $form = document.querySelectorAll('#signup-form')[0],

                    $submit = document.querySelectorAll('#signup-form input[type="submit"]')[0],

                    $message;



            // Bail if addEventListener isn't supported.

                if (!('addEventListener' in $form))

                    return;



            // Message.

                $message = document.createElement('span');

                    $message.classList.add('message');

                    $form.appendChild($message);



                $message._show = function(type, text) {



                    $message.innerHTML = text;

                    $message.classList.add(type);

                    $message.classList.add('visible');



                    window.setTimeout(function() {

                        $message._hide();

                    }, 3000);



                };



                $message._hide = function() {

                    $message.classList.remove('visible');

                };



            // Events.

            // Note: If you're *not* using AJAX, get rid of this event listener.

                $form.addEventListener('submit', function(event) {



                    event.stopPropagation();

                    event.preventDefault();



                    // Hide message.

                        $message._hide();



                    // Disable submit.

                        $submit.disabled = true;



                    // Process form.

                    // Note: Doesn't actually do anything yet (other than report back with a "thank you"),

                    // but there's enough here to piece together a working AJAX submission call that does.

                        window.setTimeout(function() {



                            // Reset form.

                                $form.reset();



                            // Enable submit.

                                $submit.disabled = false;



                            // Show message.

                                $message._show('success', 'Thank you!');

                                //$message._show('failure', 'Something went wrong. Please try again.');



                        }, 750);



                });

Code

// Process form.

            // Note: Doesn't actually do anything yet (other than report back with a "thank you"),

            // but there's enough here to piece together a working AJAX submission call that does.

            window.setTimeout(function() {



            // Reset form.

            $form.reset();



            // Enable submit.

            $submit.disabled = false;



            // Show message.

            $message._show('success', 'Thank you!');

            //$message._show('failure', 'Something went wrong. Please try again.');



             //ADD AJAX POST HERE



            }, 750);