modifier script pour erreur si element inexistant

www/css/style.css

@@ -21,6 +21,8 @@
     display: block;
     background-color: yellow;
     font-weight: bold;
+    color: black;
+    
 }
 body {
     min-height: 100vh;

www/js/script.js

@@ -1,7 +1,7 @@
 window.onload = function () {
             setTimeout(function () {
-                document.getElementById('message').innerHTML =
+/*                document.getElementById('message').innerHTML =
-                    'The page has finished loading! After 2 second';
+                    'The page has finished loading! After 2 second'; */
                     document.getElementById("updateDate").setAttribute("id", "updateDateV");
             }, 2000);
         };