ajxa跨域：http://www.cnblogs.com/sunxucool/p/3433992.html
http://www.cnblogs.com/fsjohnhuang/articles/2345653.html
http://www.tuicool.com/articles/uuiE3y
http://bbs.csdn.net/topics/390531340
http://www.cnblogs.com/dojo-lzz/p/4265637.html
原文：http://www.cnblogs.com/8899man/p/5154351.html