Código PHP:
<?php
session_start();
if (isset($_SESSION['mi_reserva'])){
$indice=count($_SESSION['mi_reserva'])+1;
}
else{
$indice = 1;
}
if (isset($_POST['enviar'])){
$reserva[$indice]["percentage"] = $_POST['percentage'];
$reserva[$indice]["llegada"] = $_POST['llegada'];
$reserva[$indice]["salida"] = $_POST['salida'];
$reserva[$indice]["propiedad"] = $_POST['propiedad'];
$_SESSION['mi_reserva'] = $reserva;
header("Location: prueba2.php");
}
?>