custome facebook login button

<img src="<?php _e(SITE_PATH); ?>/images/facelogin.png" width="237" height="45" alt="facebook" />
<script>
(function ($) {
$(function () { $("#login img").on("click", function () { FB.login(function(response) {
if (response.authResponse) { _wdfb_notifyAndRedirect(); }});});});})(jQuery);</script>

This Work Fine
But I want show a loading image , How can i set a loading image when click on that image button