How to Display new Background image after submitting php form

I would like to display a status page after the user submits a form. All I need after a user submits, is to change the background image, hide the current elements, and to add a header that says that your application is being reviewed. Attached is the jsfiddle.

https://jsfiddle.net/dreimschiissel/9Lonf5tz/3/

<div class = "biz-contact-form">
    <form id = "biz-contact-form" method = "post" action = "biz-form.php"> 

        <div class="upload-btn-wrapper">
            <input type="file" name="myfile" />
        </div>
        <br>
        <input name = "businesslicense" type="text" class = "sell-form-control" placeholder = "#####">
        <br>
        <br>
        <input type = "submit" href="#" onclick = ""  class = "sell-submit-button" value = "Submit">

    </form>
</div>