Nested Attributes in Rails 3

Question

can anyone please walk me through Nested Attributes in Rails 3?

I have two Models: Certificates and Custodians, related as follows:

Certificate Model:

<

Answer 1

This line

<% f.fields_for :custodian do |custodian| -%>

should be

<%= f.fields_for :custodian do |custodian| -%>