Foreign key dropdowns in scaffolded views

Hello,

i created 2 models using scaffolding with rails 3 the models were
locations and jobs

1) Each job has a location

i created the required reference calls in the scaffold generation code
but when i look at the view to create a new job, all i see is a
textbox where i should add the location ID.

How can i get that to be a dropdown instead for a better user
experience?

Thanks