jQuery UI 1.7.1叠加上的模态关闭单击

I'm trying to override the default behavior of a jQuery UI modal dialog box to close the box when the overlay is clicked. The code I have below will close the dialog box after I open it for the first time and click on the overlay. When I open the dialog box again, clicking on the overlay does nothing. I am missing an event here. Can someone point out what I'm doing wrong here?I'm trying to override the default behavior of