Make Live Clock with Javascript in PHP

<!-- Show Clock -->
<?php
     echo "<span id='clock' style='margin-left:10px;'></span>";
?>

<!-- Clock -->
<script type="text/javascript">
var clock = document.getElementById('clock');

function time() {
  var d = new Date();
  var s = d.getSeconds();
  var m = d.getMinutes();
  var h = d.getHours();
  clock.textContent = h + ":" + m + ":" + s;
}
setInterval(time, 1000);
</script>