AJAX fileupload – TypeError: not a function ajaxSubmit()

I have a plugin that works as a standard POST but not as an AJAX request. Really looking for any ideas of what I missed… Thank you.

I am getting a not a function error in Firebug with this function:

TypeError: jQuery(…).ajaxSubmit is not a function

jQuery(this).ajaxSubmit(options);

This is the js file that it being enqueued with my plugin – it does load in the header:

//Removed file checks that are HTML5 spec
jQuery(document).ready(function(){

     jQuery('#nannie_app_upload').submit(function() {
            var options = {
            action:         'nannie_app_upload',
            type:           "POST",
            target:         '#output',   // target element(s) to be updated with server response
            beforeSubmit:   beforeSubmit,  // pre-submit callback
            success:        afterSuccess,  // post-submit callback
            uploadProgress: OnProgress, //upload progress callback
            resetForm:      true        // reset the form after successful submit
        };             

                alert('jQuery submit called');
                jQuery(this).ajaxSubmit(options);
                // always return false to prevent standard browser submit and page navigation
                alert('Got this from the server: ' + response);
                return false;
        });

//function after succesful file upload (when server response)
function afterSuccess(){

    alert('jQuery afterSuccess');
    jQuery('#submit-btn').show(); //show submit button
    jQuery('#loading-img').hide(); //hide loading button
    jQuery('#progressbox').delay( 1000 ).fadeOut(); //hide progress bar
}

//function to check file size before uploading.
function beforeSubmit(){

    alert('jQuery beforeSubmit');
    jQuery('#submit-btn').hide(); //hide submit button
    jQuery('#loading-img').show(); //show loading button
    jQuery("#output").html("");
}

//progress bar function
function OnProgress(event, position, total, percentComplete)
{
    //Progress bar
    alert('jQuery OnProgress');
    jQuery('#progressbox').show();
    jQuery('#statustxt').show();
    jQuery('#progressbar').width(percentComplete + '%') //update progressbar percent complete
    jQuery('#statustxt').html(percentComplete + '%'); //update status text
    if(percentComplete>50)
        {
            jQuery('#statustxt').css('color','#000'); //change status text to white after 50%
        }
}

});

Here is the Form that is generated from a child theme:

//Nannie upload form
add_action("action_nannie_upload_form", "do_action_nannie_upload_form");

function do_action_nannie_upload_form()
{
    $url = plugins_url();
    $plugins_url = $url . "/nannie-app/";
    ?><br>
    An Upload FORM!<br>
    <form action="<?php echo admin_url('admin-ajax.php'); ?>"
    method="post" enctype="multipart/form-data" id="nannie_app_upload">
    <br>
        <?php wp_nonce_field('nannie_app_upload','nannie_upload_ajax_nonce'); ?>
        <!-- Add new File -->
        <span class="btn btn-file">Select file:
        <input name="FileInput" id="FileInput" type="file" /></span>
        <button type="submit" class="btn" id="submit-btn">Upload</button>
    </form>

    <img src="<?php echo $plugins_url; ?>images/ajax-loader.gif" id="loading-img"
    style="display:none;" alt="Please Wait"/>
    <div id="progressbox" style="display:none;"><div id="progressbar"></div >
    <div id="statustxt">0%</div></div>
    <div id="output"></div>
    <br>
    <br>
    <hr/>
<?php
}

And here is the action that is called by the form submit. If I remove the check for AJAX headers it uploads the file and redirects me to a blank page.

add_action("wp_ajax_nopriv_nannie_app_upload", "nannie_app_upload");

function nannie_app_upload(){
    global $wpdb;   

    if(isset($_FILES["FileInput"])){
        log_me("nannie_app_upload: FileInput found");

    if (!isset( $_POST['nannie_upload_ajax_nonce']) ||
       !wp_verify_nonce($_POST['nannie_upload_ajax_nonce'], 'nannie_app_upload')){
       print 'Sorry, your nonce did not verify.';
       log_me("nannie_app_upload: nonce did not verify");
       exit;
    }

    if (!isset($_SERVER['HTTP_X_REQUESTED_WITH'])){
        if(isset($_SESSION["naap_app_uid"])){
             $app_uid = $_SESSION["naap_app_uid"];
        }
        log_me('nannie_app_upload: AJAX Not Called #' . $app_uid);
        die();
    }

    //Is file size is less than allowed size.
    if ($_FILES["FileInput"]["size"] > 5242880) {
        log_me('nannie_app_upload: File size is too big! #' . $app_uid);
        die("File size is too big!");
    }       

    $_SESSION["naap_app_uid"] = $app_uid;
    $UploadDirectory = WP_PLUGIN_DIR."/nannie-app/tmp/" . $app_uid . "/";

        ////////////////////////////////////////////////////
        //http://www.saaraan.com/2012/06/ajax-file-upload-with-php-and-jquery

        if (!@file_exists($UploadDirectory)) {
                //destination folder does not exist
            if(!is_dir($UploadDirectory)) {
                mkdir($UploadDirectory);
                if (!@file_exists($UploadDirectory)) {

                    log_me('nannie_app_upload: Upload directory missing for AJAX upload #' . $app_uid);
                    die("Make sure Upload directory exist!");

                }
            }
        }

        //allowed file type Server side check
        switch(strtolower($_FILES['FileInput']['type']))
        {
                //allowed file types
                case 'image/png': //png file
                case 'image/gif': //gif file
                case 'image/jpeg': //jpeg file
                case 'application/pdf': //PDF file
                case 'application/msword': //ms word file
                case 'application/vnd.ms-excel': //ms excel file
                case 'application/x-zip-compressed': //zip file
                case 'text/plain': //txt file
                case 'text/html': //html file

                        //File Title will be used as new File name
                        $FileName       = strtolower($_FILES['FileInput']['name']); //uploaded file name
                        $ImageExt       = substr($FileName, strrpos($FileName, '.')); //file extension
                        $NewFileName    = substr($FileName, 0, strrpos($FileName, '.') ); //file name before random 

                        $FileType       = $_FILES['FileInput']['type']; //file type
                        $FileSize       = $_FILES['FileInput']["size"]; //file size

                        $RandNumber     = rand(0, 9999999999); //Random number to make each filename unique.
                        $uploaded_date  = date("Y-m-d H:i:s");

                        $NewFileName = preg_replace(array('/\s/', '/\.[\.]+/', '/[^\w_\.\-]/'), array('_', '.', ''), strtolower($NewFileName));
                        $NewFileName = $NewFileName.'_'.$RandNumber.$ImageExt;

                        //Rename and save uploded file to destination folder.
                        if(move_uploaded_file($_FILES['FileInput']["tmp_name"], $UploadDirectory . $NewFileName )){
                                    //future SQL Insert to record the files uploaded - new table napp_applications_files
                                    log_me('nannie_app_upload: Success Upload #' . $app_uid);
                                    die('Success! File Uploaded.');
                                    break;

                        }else{
                                    log_me('nannie_app_upload: Failed Upload #' . $app_uid);
                                    die('error uploading File!');
                                    break;
                        }            

                        break;
                default:
                        log_me('nannie_app_upload: Unsupported Upload #' . $app_uid);
                        die('Unsupported File!'); //output error enforcing file types
                        break;
        }

    }else{
        log_me('nannie_app_upload: Something wrong with upload! Is "upload_max_filesize" set correctly? #' . $app_uid);
        die('Something wrong with upload! Is "upload_max_filesize" set correctly?');
    }
}