/**
 * Function getting how many nights will the persons stay in a selected apartment.
 * Function invokes ajax.
 */
function setApartmentNights() {
        var iApartmentId = document.getElementById('iReservationApartmentId').value;
        postString = "&aid=" + iApartmentId;
        var iDay = document.getElementsByName('sStartDateDay')[0].value;
        var iMonth = document.getElementsByName('sStartDateMonth')[0].value;
        var iYear = document.getElementsByName('sStartDateYear')[0].value;
        postString += "&sBeginDate=" + iYear + "-" + iMonth + "-" + iDay;
        var iDay = document.getElementsByName('sEndDateDay')[0].value;
        var iMonth = document.getElementsByName('sEndDateMonth')[0].value;
        var iYear = document.getElementsByName('sEndDateYear')[0].value;
        postString += "&sEndDate=" + iYear + "-" + iMonth + "-" + iDay;
        jQuery.ajax({
                beforeSend: function() {
                        //loaderSearchClient();
                        /* deactivating the "continue" button */
                        jQuery('#continue_button').attr('disabled','disabled');
                        jQuery('#iApartmentCountNights').html('<img src="logic_frontend/templates/site/images/ajax-loader3.gif" />');
                },
                type: "POST",
                url: "ajaxindex.php",
                data: "mod=apart&sec=_ajax_reservation_add_count_nights"+postString,
                success: function(data, status){
                        clearToCheck();
                        
                        jQuery('#iApartmentCountNights').html(data);
                        /* activating the "continue" button */
                        jQuery('#continue_button').attr('disabled','');
                }
        });
}