When /^(?:|I )fill in the (\d+)(?:st|nd|rd|th) field of "([^"]*)" with "([^"]*)"$/ do |pos, field, value|
  raise NotImplementedError unless pos.to_i == 1
  
  within(find(:xpath, "//fieldset[#{pos.to_i}]")) do
    fill_in(field, :with => value)