Index: openacs-4/packages/proctoring-support/www/resources/proctored-page.js
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/proctoring-support/www/resources/Attic/proctored-page.js,v
diff -u -r1.1.2.28 -r1.1.2.29
--- openacs-4/packages/proctoring-support/www/resources/proctored-page.js	15 Dec 2022 11:40:32 -0000	1.1.2.28
+++ openacs-4/packages/proctoring-support/www/resources/proctored-page.js	15 Dec 2022 13:36:05 -0000	1.1.2.29
@@ -18,7 +18,7 @@
 }
 
 function embedAudioTrackFromStream(fromStream, toStream) {
-    if (fromStream === undefined) {
+    if (typeof fromStream === 'undefined') {
         return;
     }
     const audioTracks = fromStream.getAudioTracks();
@@ -318,15 +318,15 @@
                 // If user requested for a specific displaysurface
                 // and browser supports it, also check that the
                 // one selected is right.
-                if (requestedStream === undefined ||
-                    (selectedStream !== undefined &&
+                if (typeof requestedStream === 'undefined' ||
+                    (typeof selectedStream !== 'undefined' &&
                      requestedStream === selectedStream)) {
                     deskvideo.srcObject = stream;
                     deskvideo.style.display = 'block';
                     valid = true;
                     streams[2] = stream;
                 } else {
-                    if (selectedStream !== undefined) {
+                    if (typeof selectedStream !== 'undefined') {
                         throw wrongDisplaySurfaceSelectedMessage;
                     } else {
                         throw displaySurfaceNotSupportedMessage;