Onkeyup javascript error to calculate change

Im trying to auto calculate change using javascripts when i put some number in pay the change input will auto fill with change

<!DOCTYPE html>
<html>
<body>


subtotal: <input type="number" id="subtotal" value="20000">
pay : <input type="number" id="dibayar" onkeyup="kembalian()">

<p>change: <span id="demo"></span></p>

<script>
function kembalian() {
        var x = document.getElementById("subtotal").value;
        var y = document.getElementById("dibayar").value;
        var awe = x - y;
        console.log(awe);
document.getElementById("kembalian").innerHTML = awe;
        }

</script>

</body>
</html>

Solution

you need to insert it into demo id

function kembalian() {
  var x = document.getElementById("subtotal").value;
  var y = document.getElementById("dibayar").value;
  var awe = x - y;
  console.log(awe);
  document.getElementById("demo").innerHTML = awe;
}

subtotal: <input type="number" id="subtotal" value="20000"> pay : <input type="number" id="dibayar" onkeyup="kembalian()">

<p>change: <span id="demo"></span></p>