Getting drop-down selection on a "new" view to controller

On a “new” view, there’s two drop-down lists - Company and Contact.
They both display the name, but store the id. After changing the
company drop-down list, I want to limit the Contact drop-down list to
only Contacts for the selected Company.

I added a function call to the OnChange event of the company drop-down
list:
{:onChange => remote_function(:url => { :action =>
‘update_contact_list’, :company_id => quote.company_id }) }

And then I have this is the Controller:
def update_contact_list
@company = Company.find(params[:company_id])
@contact_list = Contact.find(:all, :order => :first_name,
:conditions => [ “company_id =?”, @company ])
render :update do |page|
page.replace_html ‘contact_list’, ‘collection_select :quote,
:contact_id, @contact_list, :id, :first_name, { :include_blank => true,
:multiple => false } , :html => { :id => “contact_list” }’

  end

end

It’s complaining that “quote” (in the “quote.company_id” part of the
OnChange code in the view) is nil. Which I suppose it is, since the
record hasn’t been saved yet. What’s the best way to handle that? The
company drop-down is the first thing on the page (or in other words,
it’s the first field users are going to enter data into - so, saving the
record before they get to that point isn’t a great option). Is there
another way to pass the value they just selected to the controller?

Thanks!