action not found in testing Ajax call

I have a route defined as :

change_area_backoffice_regions GET /backoffice/regions/ change_area(.:format) backoffice/regions#change_area

I am testing using the following functional test :

  test "should list regions in another area" do     south_west = FactoryGirl.create(:area, name: "South West)     new_mexico = FactoryGirl.create(:region, area: south_west, code: "72") # here is my call     xhr :get, :change_area => { :area => south_west[:id]} # sending the area[:id] as a parameter     assert_select "a", {:count => 1, :text => "New Mexico"}, "Wrong name or more than one region element"   end

but I get a route error : AbstractController::ActionNotFound: The action '{:change_area=>{:area=>20}}' could not be found for Backoffice::RegionsController this action is defined , and the route is there , what's wrong with y test code ?

  def change_area     @area = Area.find(params[:area])     @regions = @area.regions     render "backoffice/regions/change_area.js"   end

thanks for any feedback

[SOLVED] I re-read the error message, and it's so obvious : The

'{:change_area=>{:area=>20}}'

I wrote a '=>" in place of a comma .... but it's Sunday ... I should clue my computer and go to the beach ...