Only allow submission of the form when it is filled out

Before:
![screen shot 2014-10-06 at 11 26 39 am](https://cloud.githubusercontent.com/assets/5728307/4531034/6130ac4e-4d86-11e4-981d-266ac565f8a3.png)

```formIsValid``` should probably be false if ```formIsFilled``` is false, but I am fine with this fix.