Update index.html

index.html

@@ -17,9 +17,12 @@
 			</p>
 		</div>
           <script>
-            const header = document.querySelector("header");
+            (function () {
+                          const header = document.querySelector("header");
             header.style.display = "none";
             alert("Hiding")
+            })();
+
           </script>
 	</body>
 </html>