$(".calender_box").datepicker({
                buttonImage: '<?php echo $this->webroot .  "img/calendar.gif";?>',
                buttonImageOnly: true,
                changeMonth: true,
                changeYear: true,
                showOn: 'both',
                dateFormat: "dd-mm-yy",
                minDate: $.datepicker.formatDate('dd-mm-yy', new Date()),
                onSelect: function( selectedDate ) {
                    $.ajax({
                        url: BASE_URL + "incident_notes/getintervel/",
                        async:false,
                        data: {selectedDate:selectedDate},
                        type:"POST",
                    }).done(function(data) {
                        alert($(this).closest("input[type='hidden']").val());
                    });
                },
                onClose: function(selectedDate){

                }
             });