question about form with one-to-one models

For example, I have two models Person and Address, that one person has one address.

class Person < ActiveRecord::Base has_one :address end

class Address < ActiveRecord::Base belongs_to :person

end

Now, I want to write a form to create a person including an address

Name
<%= text_field 'person', 'name', :size => 10 %>

Country
<%= text_field 'person', 'address.country' %>

# i think it will map to person.address.country , but it doesn't work, how can i do it? ......