diff --git a/simpledemo.html b/simpledemo.html
index bb50b23..4ab2e8c 100644
--- a/simpledemo.html
+++ b/simpledemo.html
@@ -530,8 +530,11 @@
 <script src='https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/js/bootstrap.bundle.min.js'
         integrity='sha384-C6RzsynM9kWDrMNeT87bh95OGNyZPhcTNXj1NW7RuBCsyN/o0jlpcV8Qyq46cDfL' crossorigin='anonymous'></script>
 <script type="text/javascript">
-    function isValidIP(ipaddress) {
-        if (/^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(ipaddress)) {
+    function isValidIPorFQDN(address) {
+        if (/^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(address)) {  // regex from https://www.w3resource.com/javascript/form/ip-address-validation.php
+            return true;
+        }
+        if (/^(?!:\/\/)(?!.{256,})(([a-z0-9][a-z0-9_-]*?\.)+?[a-z]{2,6}?)$/i.test(address)) {  // regex from https://stackoverflow.com/questions/16463666/javascript-regex-to-match-fully-qualified-domain-name-without-protocol-optiona
             return true;
         }
         return false;
@@ -774,7 +777,7 @@
         setInterval(updateStrings, 10000);
     }
     window.onload = function(e) {
-        if (document.cookie == "" || !isValidIP(document.cookie)) {
+        if (document.cookie == "" || !isValidIPorFQDN(document.cookie)) {
             var selectIPModal = new bootstrap.Modal(document.getElementById('selectIPAddressModal'), {});
             selectIPModal.show();
 
@@ -782,7 +785,7 @@
 
             function configButtonEventListener(hideModalOnSuccess) {
                 var ipAddressEntered = document.getElementById('ipAdressInput').value;
-                if(isValidIP(ipAddressEntered)) {
+                if(isValidIPorFQDN(ipAddressEntered)) {
                     var request = new XMLHttpRequest();
                     request.onreadystatechange = function() {
                         if (this.readyState == 4 && this.status == 200) {
@@ -811,7 +814,7 @@
             const ipAdressModalOkBtn = document.getElementById('ipAdressModalOkBtn');
             ipAdressModalOkBtn.addEventListener('click', () => { configButtonEventListener(true); });
 
-        } else if (isValidIP(document.cookie)) setupSite();
+        } else if (isValidIPorFQDN(document.cookie)) setupSite();
     }  // end of onload function
 </script>
 </body>