customize error for rails

I have used following code for showing errors on a individual field
level

ActionView::Base.field_error_proc = Proc.new do |html_tag, instance|
  %{#{html_tag}&nbsp;<div
class="formError">#{[instance.error_message].flatten.first}</div>}
  end

but it showing errors for label as well as for text field how to add
modification so that it will show error only once?