Date.prototype.addDays = function (days) {
    this.setDate(this.getDate() + days);
}

$(document).ready(function () {

    var modern_v_orange_dateformat = $('#modern_v_orange_df').val();
    var modern_v_orange_locale = $('#modern_v_orange_locale').val();
    var modern_v_orange_nights = parseInt($('#modern_v_orange_nights').val());

    $.datepicker.setDefaults($.datepicker.regional[modern_v_orange_locale]);

    $("#modern_v_orange_ci").datepicker({
        showOn: "button",
        buttonImage: "http://www.geobookings.com/data/forms/modern_v_orange/images/calendar.jpg",
        buttonImageOnly: true,
        changeMonth: true,
        changeYear: true,
        minDate: 0,
        dateFormat: modern_v_orange_dateformat,
        onSelect: function (dateText, inst) {
            sDate = $("#modern_v_orange_ci").datepicker("getDate");
            sDate.addDays(modern_v_orange_nights);
            $("#modern_v_orange_co").datepicker("setDate", sDate);
        }
    });
    $("#modern_v_orange_ci").datepicker($.datepicker.regional[modern_v_orange_locale]).datepicker("setDate", "+0d");

    $("#modern_v_orange_co").datepicker({
        showOn: "button",
        buttonImage: "http://www.geobookings.com/data/forms/modern_v_orange/images/calendar.jpg",
        buttonImageOnly: true,
        changeMonth: true,
        minDate: 1,
        changeYear: true,
        dateFormat: modern_v_orange_dateformat
    });
    $("#modern_v_orange_co").datepicker($.datepicker.regional[modern_v_orange_locale]).datepicker("setDate", "+" + modern_v_orange_nights + "d");

    $("#modern_v_orange_go").click(function () {
        var id = $('#modern_v_orange_id').val();
        var lid = $('#modern_v_orange_lid').val();
        var interface = $('#modern_v_orange_interface').val();
        var theme = $('#modern_v_orange_theme').val();
        var ci = $('#modern_v_orange_ci').val();
        var co = $('#modern_v_orange_co').val();
        var windowname = "geobooking" + id;
        window.open(interface + '&ci=' + ci + '&co=' + co, windowname, '');
    });

});