diff --git a/chapter04/src/cors_request.html b/chapter04/src/cors_request.html
new file mode 100644
index 0000000..cd7240e
--- /dev/null
+++ b/chapter04/src/cors_request.html
@@ -0,0 +1,23 @@
+<html>
+
+<head></head>
+
+<body>
+    <script type="text/javascript">
+        const req = new XMLHttpRequest();
+        req.open('GET', 'http://www.corsserver.com:8080/', true);
+        req.onreadystatechange = () => {
+            if (req.readyState === 4) {
+                if (req.status >= 200 && req.status < 400) {
+                    console.log(req.responseText)
+                } else {
+                    console.warn("Problems!")
+                }
+            }
+        };
+        //        req.setRequestHeader("dummy", "value");
+        req.send();
+    </script>
+</body>
+
+</html>
\ No newline at end of file
