diff --git a/categories.js b/categories.js
index ead8d16..3501b71 100644
--- a/categories.js
+++ b/categories.js
@@ -8,6 +8,10 @@ for(var i = 0; i < categories.length; ++i)
         'use strict';
         var cat_id = event.target.id.replace('cat_','');
 
+        var xhr = new XMLHttpRequest();
+        xhr.open("GET", "updateCategories.php?id="+cat_id+"&val="+event.target.checked);
+        xhr.send(null);
+
         var events = document.getElementsByClassName('event_in_cat_'+cat_id);
 
         for(var i = 0; i < events.length; ++i)
diff --git a/updateCategories.php b/updateCategories.php
new file mode 100644
index 0000000..608b87b
--- /dev/null
+++ b/updateCategories.php
@@ -0,0 +1,10 @@
+<?php
+session_start();
+
+if(!isset($_GET['id']) || !isset($_GET['val']))
+{
+    exit;
+}
+
+$_SESSION['categorieStatus'][$_GET['id']] = $_GET['val'] == "true";
+?>