update verification code arguments

旧的验证码：
![image](https://cloud.githubusercontent.com/assets/1559832/4385984/6e9e1bb0-43cb-11e4-8233-49bcf17eece9.png)


新的验证码：
![image](https://cloud.githubusercontent.com/assets/1559832/4385977/5ff0dfbc-43cb-11e4-835a-1a1ff8b0b631.png)