PHP - XML In Sending Data

Here's a code on how to sending data from client to server in the form of xml format. You can see also at this link.
1. file index.php

<h1>Javascript And JSON</h1>
<p>Here's a demo on how to use json and ajax for sending data to server</p>
<div id="form">
    Name: <input type="text" id="name"/><br/>
    City: <input type="text" id="city"/><br/>
    Age: <input type="text" id="age"/><br/>
    <input type="button" onclick="sendData()" value="Save"/>
</div>
<div id="response"></div>

<script>

function sendData(){

    var name = document.getElementById('name');

    var city = document.getElementById('city');

    var age = document.getElementById('age');

   

    var data = '';

    var data = data + '<?xml version=\'1.0\'?>';

    var data = data + '<data>';

    var data = data + '<name>'+name.value+'</name>';

    var data = data + '<city>'+city.value+'</city>';

    var data  = data +  '<age>'+age.value+'</age>';

    var data  = data + '</data>';

   

    var parser = new DOMParser();

    var datas = parser.parseFromString(data,'text/xml');

   

    var ajax = new XMLHttpRequest();

    ajax.open("GET","hello.php?data="+data,false);

    ajax.send();

   

    name.value = '';

    city.value = '';

    age.value = '';

   

    var res = document.getElementById('response');

    res.innerHTML = ajax.responseText;

   

}

</script>

2. file: hello.php
<?php

$handle = mysql_connect("localhost","root","indonesia");
mysql_select_db("data",$handle);

$data = $_GET['data'];
$doc = new DOMDocument();
$xmlDoc = $doc->loadXML($data);

$lol = $doc->getElementsByTagName('name');
$name = $lol->item(0)->nodeValue;

$cities = $doc->getElementsByTagName('city');
$city = $cities->item(0)->nodeValue;

$ages = $doc->getElementsByTagName('age');
$age = $ages->item(0)->nodeValue;

echo $name." => ".$city." => ".$age;

$query = "INSERT INTO personal_info (name, city, age) VALUES ";
$query .= "('".$name."', '".$city."', ".$age.")";

$result = mysql_query($query);

?>

PHP - XML In Sending Data