if (timer)
       clearTimeout(timer);
   timer   = setTimeout(update, 900);
   alert("nominalIndex.js: onKeyDownName: timer=" + timer)

   alert("nominalIndex.js: update:");
   // perform the function

I have a piece of code which has worked fine since I wrote it almost 20 years ago and which has only been fine tuned as the standards for JavaScript have been refined over those two decades. The functionality is to act when the user stops typing into a textbox for 0.9 seconds, which by trial and error I found was fast enough to act without premature invocation because the user was just typing slowly. ```javascript // in the initialization code element.addEventListener('keydown', onKeyDownName); ... function onKeyDownName(event) { if (timer) clearTimeout(timer); timer = setTimeout(update, 900); alert("nominalIndex.js: onKeyDownName: timer=" + timer) } // function onKeyDownName function update() { alert("nominalIndex.js: update:"); // perform the function } ``` The alerts are only inserted, on my private test site only, to try and debug why this code is no longer working. Each time I type a character I see the alert "nominalIndex.js: onKeyDownName: timer=nnn" but no matter how long I wait I never see the alert "nominalIndex.js: update:". To get the function to work the user must take some other action which causes the function update to be called. There are no messages in the log to explain why the timer isn't popping. How can I debug this? The code works on Chromium 87.0.4280.88 but doesn't work on FireFox 83.0 build id 20201112153044. I am running Ubuntu Linux 20.04 See this code in action at www.jamescobban.net/FamilyTree/nominalIndex.php?name=Culbert%2C%20Su&treename=&lang=en