ajax 跨域访问

默认是禁止的，需要在服务器端开启。

python tornado示例

class XXXHandler(RequestHandler):

	def post(self, *args, **kwargs):
		self.set_header("Access-Control-Allow-Origin", "*")
		self.set_header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept")
		...

参考：

http://stackoverflow.com/questions/5750696/how-to-get-a-cross-origin-resource-sharing-cors-post-request-working