[Rails] question about post changes for a list of objects once

[ChongQing Xiao]

Hi, 

In the web browser, I have a grid to show a list of object (say a list
of post or appt), the user can edit individual row in the client without
post data back to server (using javascript),
After the change, the user will click a submit key to post changes back
to server and file the change once.

Does rails have some standard way to handle this?

Also for the following code (I copied from the example in active record)
logger.info "\nUsing has_and_belongs_to_many association"
david = Person.find(1)
david.add_companies(thirty_seven_signals, next_angle)

Is anyway to add the companies using company ID instead of using the
company object so I don't need to call company.FindOne("123") since I
don't need other information for the company?
-- Something like David.add_companiesByID("123")

Thanks
chong