Validate form errors

#9 
Form on load:
![add content daf](https://cloud.githubusercontent.com/assets/7369740/3875167/bd9c11e0-214d-11e4-9891-4ddaec15d3ae.png)


Form validation:
![validations](https://cloud.githubusercontent.com/assets/7369740/3875166/bd944f1e-214d-11e4-8023-a7b881e19b9c.png)