找出几篇写的好的博客:
1.http://www.cnblogs.com/wangfupeng1988/p/3977924.html
2.http://yehudakatz.com/2011/08/11/understanding-javascript-function-invocation-and-this/?cm_mc_uid=67042114864314475037022&cm_mc_sid_50200000=1447503702 (需要FQ)