Make 'or' align at center.

Fix the wrong position of 'or', the following images show the result.

![screen shot 2014-07-27 at 12 32 18 am](https://cloud.githubusercontent.com/assets/1086008/3711670/295805cc-14e4-11e4-8b1d-f31af8a440be.png)

![screen shot 2014-07-27 at 12 32 59 am](https://cloud.githubusercontent.com/assets/1086008/3711671/295b5754-14e4-11e4-8fa1-d7ed91947c43.png)

Signed-off-by: Jia-He Jou <joujiahe@gmail.com>