Fix example code syntax

before:
![2014-07-04 23 23 05](https://cloud.githubusercontent.com/assets/290782/3482888/cf757684-0386-11e4-87e9-afbebbca66fa.png)

after:
![2014-07-04 23 23 26](https://cloud.githubusercontent.com/assets/290782/3482891/da28efac-0386-11e4-81de-22e3312b57ce.png)