<!DOCTYPE html>
<html lang="en-US">
<body>
<p>Open your console (Press F12) and then type something into the input field.</p>
<input onkeyup="myLockElement()" onfocus="myFunction()" type="text">
<p><strong>Note</strong>: Once you focus the input field, your mouse pointer will disappear. Press 'Esc' to get back the mouse pointer.</p>
<script>
var inp = document.getElementsByTagName("input")[0];
function myFunction(){
if(document.pointerLockElement == null)
inp.requestPointerLock();
}
function myLockElement(){
console.log(document.pointerLockElement);
}
</script> </body>
</html>