code: def validate_presence(field, value, setting)
        if(value.is_a?(Numeric))
          return true
        elsif value.is_a?(String) || value.nil?
          result = value.nil? || ((value.length == 0) == setting)
          additional_message = setting ? "non-empty" : "non-empty"
          add_message(field, "incorrect value supplied for #{field.to_s} -- should be #{additional_message}.") if result
          return !result
        end
        return false
      end
docs: Validates that something has been endntered in a field.
   Should catch Fixnums, Bignums and Floats. Nils and Strings should
   be handled as well, Arrays, Hashes and other datatypes will not.