Iam trying to disabling the range of date selected from datepicker?. but getting error Object doesn't support this property or method..please help it guys..

$('.thing12DatePicker').datepicker( { //beforeShowDay: $.datepicker.noWeekends, beforeShowDay: function (date) { var startDate = "2014-06-15", // some start date endDate = "2014-06-21", // some end date dateRange = []; // array to hold the range // populate the array for (var d = new Date(startDate); d <= new Date(endDate); d.setDate(d.getDate() + 1)) { dateRange.push($.datepicker.formatDate('yy-mm-dd', d)); } var dateString = jQuery.datepicker.formatDate('yy-mm-dd', date); return [dateRange.indexOf(dateString) == -1]; } });