convert new line (in textarea) to br tag using javascript and php

[-------------------------------- using javascript ------------------------------ ]

var str = document.getElementById("heading_description").value;
var res = str.replace(/\n/g, '<br />');
document.getElementById("your_id").value=res;

[-------------------------------- using PHP ------------------------------- ]
<?php
function nl2br2($string) {
$string = str_replace(array("\r\n", "\r", "\n"), "<br />", $string);
echo $string;
}

$data="

sdfdsf

sdf
sdfds
fsdf

";

nl2br2($data);
?>