Improve Navigation


![3](https://cloud.githubusercontent.com/assets/5505691/2616902/0fb38334-bc0c-11e3-955a-94a98fd9f928.png)
![2](https://cloud.githubusercontent.com/assets/5505691/2616903/0fca6662-bc0c-11e3-89f8-72765e75d556.png)
![1](https://cloud.githubusercontent.com/assets/5505691/2616904/0fccc60a-bc0c-11e3-9166-b5bc6132a498.png)


Signed-off-by: Edward Cheng &lt;c4150221@gmail.com>