diff -r 000000000000 -r 6474c204b198 xulrunner/examples/simple/content/simple.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xulrunner/examples/simple/content/simple.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,17 @@
+/* vim:set ts=2 sw=2 sts=2 et cin: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+function onButtonClick() {
+  var textbox = document.getElementById("textbox");
+
+  var contractid = (textbox.value % 2 == 0) ?
+      "@test.mozilla.org/simple-test;1?impl=js" :
+      "@test.mozilla.org/simple-test;1?impl=c++";
+
+  var test = Components.classes[contractid].
+      createInstance(Components.interfaces.nsISimpleTest);
+
+  textbox.value = test.add(textbox.value, 1);
+}