Topic: Need help for dynamic webpage design.

First of all, I apologize for my shitty English. I am not a native English-speaker.
Everyone has the experience of applying a job on the company website.
It will jump out a dialogue form when you click the "add university" or "add employer".
And after you complete the form and click the save, the form will be attach to the current website.

How could I implement this process?
In my opinion, the active record association should be like this:
Class Application<ActiveRecord::Base
      has_many :universities
      has_many :employers

Class University<ActiveRecord::Base
      belongs_to :application

Class Employer<ActiveRecord::Base
      belongs_to :application

but I don't know how to fulfill the process of : clicking an "add university" button and the university form will appear the current webpage and after the user click 'Save', and it will be static on the webpage.
Thank you very much for any suggestions. smile