Every 4 or 5 times ,I must refresh my page to submit.

Challenge [Access Array Data with Indexes](https://www.freecodecamp.cn/challenges/access-array-data-with-indexes) has an issue.
User Agent is: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36.
Please describe how to reproduce this issue, and include links to screenshots if possible.

My code:
```javascript
// 举例
var ourArray = [1,2,3];
var ourData = ourArray[0]; // ourData 的值为 1

// 初始化变量
var myArray = [1,2,3];

// 请把你的代码写在这条注释以下

```