Getting Geo Location in PHP and display in PHP page

first of I am newbie to php. I am using this website tutorial to display visitor location in html5 which is working fine. Now I am trying to display visitor geolocation by pasting the following code into my php page which is not working. How can I sort this out please help me.

<script src="jquery.min.js"></script>
<script>
$(document).ready(function(){
    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(showLocation);
    } else { 
        $('#location').html('Geolocation is not supported by this browser.');
    }
});

function showLocation(position) {
    var latitude = position.coords.latitude;
    var longitude = position.coords.longitude;
    $.ajax({
        type:'POST',
        url:'getLocation.php',
        data:'latitude='+latitude+'&longitude='+longitude,
        success:function(msg){
            if(msg){
               $("#location").html(msg);
            }else{
                $("#location").html('Not Available');
            }
        }
    });
}
</script>
<?php
if(!empty($_POST['latitude']) && !empty($_POST['longitude'])){
    //Send request and receive json data by latitude and longitude
    $url = 'http://maps.googleapis.com/maps/api/geocode/json?latlng='.trim($_POST['latitude']).','.trim($_POST['longitude']).'&sensor=false';
    $json = @file_get_contents($url);
    $data = json_decode($json);
    $status = $data->status;
    if($status=="OK"){
        //Get address from json data
        $location = $data->results[0]->formatted_address;
    }else{
        $location =  '';
    }
    //Print address 
    echo $location;
}
?>