Add a bit of cleanup and comments

action.php

@@ -8,6 +8,12 @@ require_once __DIR__ . "/required.php";
 
 dieifnotloggedin();
 
+/**
+ * Redirects back to the page ID in $_POST/$_GET['source'] with the given message ID.
+ * The message will be displayed by the app.
+ * @param string $msg message ID (see lang/messages.php)
+ * @param string $arg If set, replaces "{arg}" in the message string when displayed to the user.
+ */
 function returnToSender($msg, $arg = "") {
     global $VARS;
     if ($arg == "") {

static/js/app.js

@@ -2,6 +2,6 @@
 $(document).ready(function () {
     /* Fade out alerts */
     $(".alert .close").click(function (e) {
-        $(this).parent().fadeOut('slow');
+        $(this).parent().fadeOut("slow");
     });
 });