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
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
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.