Smopp_v2/machinevalidate.js

$(document).ready(function() {
    $("#machine").change(function() {

        var machine = $("#machine").val();

        var calendar = $("#calendar").val();
        var dateget = $("#dateget").val();
        $.ajax({

            type: 'POST',
            url: 'machinedesc.php',

            data: {calendar:calendar, machine:machine, dateget:dateget},
            success: function (msg) {
                    $('#message').html(msg);
            }
        });
    });
});