jQuery UI Datepicker - 禁用特定日期

有没有（容易）的方式设置jQuery UI Datepicker以禁止选择具体的预定日期？

Is there any (easy) way to set the jQuery UI Datepicker to disallow selection of specific, predetermined days?

我能够得到这种方法但是，它会产生一个空的错误，阻止它在IE中显示。

I was able to get this approach working, however, it produces a null error which prevents it from displaying in IE.

'natDays [...]。0'是null或不是一个对象

'natDays[...].0' is null or not an object

提前感谢！

更新：如果我包含一些代码，可能有帮助吗？无论如何，大部分是从上述线程中直接得到的：

UPDATE: Might help if I included some code, right? Anyway, most of this was taken straight from the aforementioned thread:

natDays = [
        [7, 23], [7, 24], [8, 13], [8, 14], 
    ];

    function nationalDays(date) {
        for (i = 0; i < natDays.length; i++) {
            if (date.getMonth() == natDays[i][0] - 1
            && date.getDate() == natDays[i][1]) {
                return [false, natDays[i][2] + '_day'];
            }
        }
        return [true, ''];
    }

    function noWeekendsOrHolidays(date) {
        var noWeekend = $.datepicker.noWeekends(date);
        if (noWeekend[0]) {
            return nationalDays(date);
        } else {
            return noWeekend;
        }
    }


    $(function() { 
        $("#datepicker").datepicker({
            inline: true,
            minDate: new Date(2009, 6, 6), 
            maxDate: new Date(2009, 7, 14), 
            numberOfMonths: 2, 
            hideIfNoPrevNext: true,
            beforeShowDay: $.datepicker.noWeekends,
            altField: '#alternate',
        }); 
    });

再次感谢