how to read location using javascript

 <script>
var x = document.getElementById("demo");
function getLocation() {
  if (navigator.geolocation) {

      navigator.geolocation.getCurrentPosition(showPosition);
  } else {

      x.innerHTML = "Geolocation is not supported by this browser.";

    }
}


 function showPosition(position) {
  x.innerHTML = "Latitude: " + position.coords.latitude + 
  "<br>Longitude: " + position.coords.longitude; 

 }
</script>