Custom form error messages for rails and yaml.de css framework

environment.rb

# This this replacemnt for default rails field_with_errors for using http://www.yaml.de/docs/index.html#yaml-forms
# Add this to ./config/environment.rb file

ActionView::Base.field_error_proc = Proc.new do |html_tag, instance|
  if html_tag =~ /<label/
    %|<div class="ym-error"><p class="ym-message">#{[instance.error_message].join(', ')}</p>#{html_tag}</div>|.html_safe
  else
    %|<div class="ym-error">#{html_tag}</div>|.html_safe
  end
end