Added tutorial and session mechanism
diff --git a/public/js/demo/session.html b/public/js/demo/session.html
new file mode 100644
index 0000000..59cfe4f
--- /dev/null
+++ b/public/js/demo/session.html
@@ -0,0 +1,44 @@
+ <!DOCTYPE html>
+<html>
+  <head>
+    <title>Cookie demo</title>
+    <script src="../src/session.js"></script>
+    <script>
+
+var cookey;
+
+function add (val) {
+  var list = document.getElementById('number');
+  list.textContent += '-' + val;
+  cookey.set('n', list.textContent);
+};
+
+function removeCookie () {
+  cookey.clear();
+};
+
+document.addEventListener('DOMContentLoaded', function () {
+  cookey = KorAP.Session.create('peter');
+  document.getElementById('number').textContent = cookey.get('n') || '';
+
+  var elements =   document.getElementsByClassName('num');
+  for (var i = 0; i < elements.length; i++) {
+    elements[i].addEventListener(
+      'click',
+      function (e) {
+        add(this.textContent);
+      }
+    );
+  };
+});
+
+    </script>
+  </head>
+  <body>
+    <div id="number"></div>
+    <span class="num">1</span>
+    <span class="num">2</span>
+    <span class="num">3</span>
+    <div onclick="removeCookie()">remove</div>
+  </body>
+</html>