Controller instance variables not visible in helper method called from rjs template

I have the following code in an rjs template that I should like to
move to a helper method associated with the controller:

if @read_access.value == "MemberEntityAccessibility"
  page.insert_html :bottom, 'read_access_list',
                   :partial => 'grantee',
                   :collection => @read_grantees
  page.show 'set_read_member_entities'
end

I created a helper method called display_grantees and placed the above
code within it.

I then called the method from within the existing rjs template using
page.display_grantees.

I get an error complaining of a nil object for @read_access (ie.
nil.value)

If I leave the code in the rjs template, it works fine. That is, I
know the instance variables @read_access etc are being initialised
correctly.

Thanks.

I have the following code in an rjs template that I should like to
move to a helper method associated with the controller:

if @read_access.value == "MemberEntityAccessibility"
  page.insert_html :bottom, 'read_access_list',
                   :partial => 'grantee',
                   :collection => @read_grantees
  page.show 'set_read_member_entities'
end

I created a helper method called display_grantees and placed the above
code within it.

I then called the method from within the existing rjs template using
page.display_grantees.

Try calling the helper as

            controller.display_grantees(page)