Ajax con jQuery

  <input type="text" id="nombre">
        <input type="button" id="boton" value="Pinchar">

        <div id="resultado"></div>
        <script>
            $(function () {
                $('#boton').click(function () {
                    var datodelusuario = $('#nombre').val();
                    $.post("datos.php",
                            {nombre: datodelusuario},
                            function (datos, status) {

                                if (status == "success") {
                                    console.log(datos);
                                    var xmlDoc = $.parseXML(datos);
                                    console.log(xmlDoc);
                                }
                            });
                });
            })
        </script>

<?php

$nombre = filter_input(INPUT_POST, "nombre");
$server = "localhost";
$user = "root";
$password = "";
$db = "sakila";
try {
    $conn = new PDO("mysql:host=$server;dbname=$db", $user, $password, [PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES 'utf8'"]);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $sql="select * from actor where first_name like '%$nombre%'";
    
    $res=$conn->query($sql);
    $actores=$res->fetchAll();
    echo "<actores>";
    foreach($actores as $actor){
        echo "<actor><first_name>".$actor['first_name'].
                "</first_name><last_name>".$actor['last_name'].
                "</last_name></actor>";
    }
    echo "</actores>";

} catch (Exception $ex) {
    echo $ex->getMessage();
}