How can I specify the selected value in collection_select wh

Hi all,
I have a relatively simple scenario. I have a form that can have a
list of multiple phone objects in it. I’m trying to get the edit and
entry screens to work with unique field names. I have entry and
record creation working, but I’m still working on edit. Is it
possible for me to specify the value of the selected index to the
“collection_select” method via an option or html option? I read the
doc, but I can’t find what I’m looking for. Below is my code, as you
can see my field and select names are “phone_#” where # is the
iteration index, but the actual variable is “phone”.

Main form snippet

<h2>Phones</h2>
<table>
<%
n = 0
for phone in @phones do
fieldname = "phone_#{n}";
%>
<tr><td>Number:</td><td> <%= text_field_tag fieldname, phone.number%></
td> <td><%= get_phone_types fieldname%></td></tr>
<%
n += 1
end
%>
<table>

helper with get_phone_types

 #
  #Create a Phone type select List
  #Take a list of html options
  #
  def get_phone_types(fieldname)
    @phones = PhoneType.find(:all, :order => "description ASC");
    #TODO, how to assign the value from phone.phone_type.id?
    collection_select(fieldname, "phone_type_id",
@phones, :id, :description);
  end

Also, is it possible for me to call the PhoneType.find and save the
resulting array “@phones” for the life of the request across multiple
method calls? I’m assuming I just need to make @phones an instance
variable, but I’m new to ROR, and I’m unsure of the best practices for
caching domain data for selects.

Thanks,
Todd