change error message name for fields

gistfile1.rb

class User
  validates_presence_of       :terms_accepted, :message => 'must be accepted'

  protected

  HUMANIZED_ATTRIBUTES = {
    :terms_accepted => 'Terms and Conditions'
  }

  def self.human_attribute_name(attr)
    HUMANIZED_ATTRIBUTES[attr.to_sym] || super
  end
end

# Error message will become "Terms and Conditions must be accepted" instead of "Terms accepted must be accepted"