为什么我的iPhone Web应用程序没有缓存并在脱机模式下工作？

I am trying to make the iPhone cache a HTML5 web application such that I can be offline when I use it. The web application is at www.prism.gatech.edu/~gtg880f and I did not make it. I am borrowing it just to try it out.I am trying to make the iPhone cache a HTML5 we