[javascript] Detect browser or tab closing

For similar tasks, you can use sessionStorage to store data locally until the browser tab is closed.

The sessionStorage object stores data for only one session (the data is deleted when the browser tab is closed).(W3Schools)

This is my pen.

<div id="Notice">
    <span title="remove this until browser tab is closed"><u>dismiss</u>.</span>
</div>
<script>
    $("#Notice").click(function() {
     //set sessionStorage on click
        sessionStorage.setItem("dismissNotice", "Hello");
        $("#Notice").remove();
    });
    if (sessionStorage.getItem("dismissNotice"))
    //When sessionStorage is set Do stuff...
        $("#Notice").remove();
</script>