# File lib/smerf_system_helpers.rb, line 31
  def validate_mandatory_question(question, responses, form)
    # Check if the responses hash has a key equal to the question code, if
    # not we know the question has not been answered
    if (!smerf_question_answered?(question, responses))
      return "Question requires an answer" 
    else
      return nil
    end
  end