Have a look in this hash - if the movie is not known it will return an error:

![image](https://f.cloud.github.com/assets/3854347/2340957/3db1f220-a4ce-11e3-9530-0c98073630cd.png)

-Store the error value in an instance variable in your route; 
![image](https://f.cloud.github.com/assets/3854347/2340963/5ea77a22-a4ce-11e3-8978-6a7f119d50a3.png)