close #868 add margin to cancel btn

事前
![2014-11-19 12 52 58](https://cloud.githubusercontent.com/assets/980357/5100525/0cb8e56e-6feb-11e4-8a0c-4add7b089919.png)

事後
![2014-11-19 12 50 47](https://cloud.githubusercontent.com/assets/980357/5100511/eecf2cfc-6fea-11e4-9c59-2dfabe8340d9.png)