Radio buttons only enhanced in first visit, but not in all following visits

Radio buttons only enhanced in first visit, but not in all following visits

I dynamically create a dialog page, and inject two radio buttons into it. The codes works well only for the first visit. In the following visits, strangely the radio buttons are not enhanced.
The codes are at http://jsfiddle.net/BScLu/. You can open, close, and re-open the dialog, to try out.