I have this web page that is already in fullscreen mode. Now, when testing with Google Chrome, if I make a call to the alert function, the page would quit fullscreen mode.

While I understand that this might be standard behavior, I would still like to make the page re-enter fullscreen mode after quitting it. I now have this function:

function enterFullScreen() {
    let element = document.documentElement;
    if (element.requestFullscreen) {
        element.requestFullscreen();
    }
    else if (element["mozRequestFullScreen"]) {
        element["mozRequestFullScreen"]();
    }
    else if (element["webkitRequestFullscreen"]) {
        element["webkitRequestFullscreen"]();
    }
    else if (element["msRequestFullscreen"]) {
        element["msRequestFullscreen"]();
    }
}

It works fine when I run it directly in the console, but when I put it after the alert call, believing it would make the page re-enter fullscreen mode, it ceases to work:

elem.onclick = function () {
    alert("something");
    enterFullScreen(); // Nothing happens what-so-ever. No errors either.
}

What might be the problem to this?