Check if the input didn't match any of your regexp. If it didn't just do a `return;`.

![screen shot 2014-01-07 at 2 24 40 pm](https://f.cloud.github.com/assets/81969/1862429/627b454a-77d1-11e3-8bf7-a9c28d386c84.png)

![screen shot 2014-01-07 at 2 25 01 pm](https://f.cloud.github.com/assets/81969/1862433/6c5b5eec-77d1-11e3-865a-e29c99d7e18b.png)

![screen shot 2014-01-07 at 2 25 16 pm](https://f.cloud.github.com/assets/81969/1862438/7dd06956-77d1-11e3-9951-3ccc4bb72547.png)