Count characters in textfield on keydown event

<script type="text/javascript">

function doThis() {
 x = document.getElementById("area").value;
 y = x.length;
 document.getElementById("demo").innerHTML = y;
}

</script>


<textarea id="area" onkeyup="doThis()"></textarea>
<p id="demo">Count goes here</p>


Output :)

1)

2)

3)