页面挂起对GAE的Ajax请求

I've created a page that interacts with an app written with Python on GAE, to return JSON data (via JSONP, because Cross-origin stuff). However, no matter what method I use, the page always hangs and data never actually makes it to the screen. It runs just fine if I request the stuff by typing the appspot URL into my address bar, though.I've created a page that interacts with an app